Solid-state imaging device and electronic apparatus

ABSTRACT

The quantum efficiency can be improved. A solid-state imaging device according to an embodiment includes: a plurality of pixels ( 110 ) arranged in a matrix, in which each of the pixels includes a first semiconductor layer ( 35 ), a photoelectric conversion section (PD 1 ) disposed on the first semiconductor layer on a side of a first surface, an accumulation electrode ( 37 ) disposed on the first semiconductor layer close to a side of a second surface on a side opposite to the first surface, a wiring ( 61, 62, 63, 64 ) extending from the second surface of the first semiconductor layer, a floating diffusion region (FD 1 ) connected to the first semiconductor layer via the wiring, and a first gate ( 11 ) that forms a potential barrier in a charge flow path from the first semiconductor layer to the floating diffusion region via the wiring.

FIELD

The present disclosure relates to a solid-state imaging device and anelectronic apparatus.

BACKGROUND

In recent years, a stacked-type image sensor in which a plurality ofphotoelectric conversion elements is stacked in a substrate thicknessdirection of a semiconductor substrate has been proposed. For example,Patent Literature 1 proposes, as a method for solving false colors, astacked-type solid-state imaging device in which photoelectricconversion regions that photoelectrically convert light of respectivewavelengths of green, blue, and red are stacked in the longitudinaldirection of the same pixel, and the green photoelectric conversionregion is constituted by an organic photoelectric conversion film. Inaddition, Patent Literature 2 proposes a structure in which chargesgenerated by photoelectric conversion and accumulated on the upper sideof the accumulation electrode are transferred in the longitudinaldirection to a collection electrode installed below the accumulationelectrode.

CITATION LIST Patent Literature

Patent Literature 1: JP 2017-157816 A

Patent Literature 2: JP 2016-63156 A

SUMMARY Technical Problem

However, in the conventional stacked-type solid-state imaging device,there is a problem that the charges generated in the organicphotoelectric conversion film cannot be efficiently stored in thesemiconductor layer positioned below the organic photoelectricconversion film, decreasing the quantum efficiency.

Therefore, the present disclosure proposes a solid-state imaging deviceand an electronic apparatus capable of improving quantum efficiency.

Solution to Problem

To solve the problems described above, a solid-state imaging deviceaccording to an embodiment of the present disclosure includes: aplurality of pixels arranged in a matrix, wherein each of the pixelsincludes a first semiconductor layer, a photoelectric conversion sectiondisposed on the first semiconductor layer on a side of a first surface,an accumulation electrode disposed on the first semiconductor layerclose to a side of a second surface on a side opposite to the firstsurface, a wiring extending from the second surface of the firstsemiconductor layer, a floating diffusion region connected to the firstsemiconductor layer via the wiring, and a first gate that forms apotential barrier in a charge flow path from the first semiconductorlayer to the floating diffusion region via the wiring.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram depicting a schematic configurationexample of an electronic apparatus according to one embodiment.

FIG. 2 is a block diagram depicting a schematic configuration example ofa distance measuring device using an electronic apparatus according toone embodiment.

FIG. 3 is a block diagram depicting a schematic configuration example ofan image sensor in one embodiment.

FIG. 4 is a diagram depicting a stacked structure example of the imagesensor according to one embodiment.

FIG. 5 is a schematic diagram depicting a schematic configurationexample of a pixel array section according to one embodiment.

FIG. 6 is a circuit diagram depicting a schematic configuration exampleof a unit pixel according to one embodiment.

FIG. 7 is a circuit diagram depicting a schematic configuration exampleof a unit pixel according to a modification of one embodiment.

FIG. 8 is a cross-sectional diagram depicting a cross-sectionalstructure example of the image sensor according to one embodiment.

FIG. 9 is a schematic diagram depicting a schematic configurationexample of a unit pixel according to a modification of one embodiment.

FIG. 10 is a circuit diagram depicting a schematic configuration exampleof a unit pixel according to a modification of one embodiment.

FIG. 11 is a cross-sectional diagram depicting a cross-sectionalstructure example of an image sensor according to a modification of oneembodiment.

FIG. 12 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a first example of oneembodiment.

FIG. 13 is a horizontal cross-sectional diagram depicting an A-A crosssection in FIG. 12 .

FIG. 14 is a horizontal cross-sectional diagram depicting anotherexample of the A-A cross section in FIG. 12 .

FIG. 15 is a horizontal cross-sectional diagram depicting still anotherexample of the A-A cross section in FIG. 12 .

FIG. 16 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a second example ofone embodiment.

FIG. 17 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a third example of oneembodiment.

FIG. 18 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a fourth example ofone embodiment.

FIG. 19 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a fifth example of oneembodiment.

FIG. 20 is a horizontal cross-sectional diagram depicting a B-B crosssection in FIG. 19 .

FIG. 21 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a sixth example of oneembodiment.

FIG. 22 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a seventh example ofone embodiment.

FIG. 23 is a horizontal cross-sectional diagram depicting a C-C crosssection in FIG. 22 .

FIG. 24 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to an eighth example ofone embodiment.

FIG. 25 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a ninth example of oneembodiment.

FIG. 26 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 10th example of oneembodiment.

FIG. 27 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 11th example of oneembodiment.

FIG. 28 is a vertical cross-sectional diagram depicting across-sectional structure example of a pixel according to a 12th exampleof one embodiment.

FIG. 29 is a vertical cross-sectional diagram depicting across-sectional structure example of a pixel according to a 13th exampleof one embodiment.

FIG. 30 is a vertical cross-sectional diagram depicting anothercross-sectional structure example of a pixel according to the 13thexample of one embodiment.

FIG. 31 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 14th example of oneembodiment.

FIG. 32 is a horizontal cross-sectional diagram depicting a D-D crosssection in FIG. 31 .

FIG. 33 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 15th example of oneembodiment.

FIG. 34 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 16th example of oneembodiment.

FIG. 35 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 17th example of oneembodiment.

FIG. 36 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to an 18th example of oneembodiment.

FIG. 37 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 19th example of oneembodiment.

FIG. 38 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 20th example of oneembodiment.

FIG. 39 is a vertical cross-sectional diagram depicting anothercross-sectional structure of a pixel according to the 20th example ofone embodiment.

FIG. 40 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 21st example of oneembodiment.

FIG. 41 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 22nd example of oneembodiment.

FIG. 42 is a horizontal cross-sectional diagram depicting an E-E crosssection in FIG. 41 .

FIG. 43 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 23rd example of oneembodiment.

FIG. 44 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 24th example of oneembodiment.

FIG. 45 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 25th example of oneembodiment.

FIG. 46 is a horizontal cross-sectional diagram depicting an F-F crosssection in FIG. 45 .

FIG. 47 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 26th example of oneembodiment.

FIG. 48 is a horizontal cross-sectional diagram depicting a G-G crosssection in FIG. 47 .

FIG. 49 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 27th example of oneembodiment.

FIG. 50 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 28th example of oneembodiment.

FIG. 51 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 29th example of oneembodiment.

FIG. 52 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 30th example of oneembodiment.

FIG. 53 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 31st example of oneembodiment.

FIG. 54 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 32nd example of oneembodiment.

FIG. 55 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 33rd example of oneembodiment.

FIG. 56 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 34th example of oneembodiment.

FIG. 57 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 35th example of oneembodiment.

FIG. 58 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 36th example of oneembodiment.

FIG. 59 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 37th example of oneembodiment.

FIG. 60 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 38th example of oneembodiment.

FIG. 61 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 39th example of oneembodiment.

FIG. 62 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 40th example of oneembodiment.

FIG. 63 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 41st example of oneembodiment.

FIG. 64 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 42nd example of oneembodiment.

FIG. 65 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 43rd example of oneembodiment.

FIG. 66 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 44th example of oneembodiment.

FIG. 67 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 45th example of oneembodiment.

FIG. 68 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 46th example of oneembodiment.

FIG. 69 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 47th example of oneembodiment.

FIG. 70 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 48th example of oneembodiment.

FIG. 71 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 49th example of oneembodiment.

FIG. 72 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 50th example of oneembodiment.

FIG. 73 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to a 51st example of oneembodiment.

FIG. 74 is a vertical cross-sectional diagram depicting across-sectional structure example of an image sensor according to afirst variation of the present disclosure.

FIG. 75 is a horizontal cross-sectional diagram depicting an I-I crosssection in FIG. 74 .

FIG. 76 is a vertical cross-sectional diagram depicting across-sectional structure example of an image sensor according to asecond variation of the present disclosure.

FIG. 77 is a horizontal cross-sectional diagram depicting an II-II crosssection in FIG. 76 .

FIG. 78 is a block diagram depicting a configuration example of anembodiment of an imaging device as an electronic apparatus to which thepresent disclosure is applied.

FIG. 79 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 80 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

FIG. 81 is a view depicting an example of a schematic configuration ofan endoscopic surgery system.

FIG. 82 is a block diagram depicting an example of a functionalconfiguration of a camera head and a camera control unit (CCU).

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the drawings. Note that, in each of thefollowing embodiments, the same parts are denoted by the same referencenumerals, and redundant description will be omitted.

In addition, the present disclosure will be described according to thefollowing item order.

1. One embodiment

1.1 System configuration example

1.2 Configuration example of solid-state imaging device

1.3 Stacked structure example of solid-state imaging device

1.4 Configuration example of unit pixel

1.5 Circuit configuration example of unit pixel

1.5.1 Modification of circuit configuration

1.6 Cross-sectional structure example of unit pixel

1.7 Material of each layer

1.8 Modification of unit pixel

1.8.1 Configuration example of unit pixel

1.8.2 Circuit configuration example of unit pixel

1.8.3 Cross-sectional structure example of unit pixel

1.9 Improvement of quantum efficiency

1.9.1 First example

1.9.2 Second example

1.9.3 Third example

1.9.4 Fourth example

1.9.5 Fifth example

1.9.6 Sixth example

1.9.7 Seventh example

1.9.8 Eighth example

1.9.9 Ninth example

1.9.10 10th example

1.9.11 11th example

1.9.12 12th example

1.9.13 13th example

1.9.14 14th example

1.9.15 15th example

1.9.16 16th example

1.9.17 17th example

1.9.18 18th example

1.9.19 19th example

1.9.20 20th example

1.9.21 21st example

1.9.22 22nd example

1.9.23 23rd example

1.9.24 24th example

1.9.25 25th example

1.9.26 26th example

1.9.27 27th example

1.9.28 28th example

1.9.29 29th example

1.9.30 30th example

1.9.31 31st example

1.9.32 32nd example

1.9.33 33rd example

1.9.34 34th example

1.9.35 35th example

1.9.36 36th example

1.9.37 37th example

1.9.38 38th example

1.9.39 39th example

1.9.40 40th example

1.9.41 41st example

1.9.42 42nd example

1.9.43 43rd example

1.9.44 44th example

1.9.45 45th example

1.9.46 46th example

1.9.47 47th example

1.9.48 48th example

1.9.49 49th example

1.9.50 50th example

1.9.51 51st example

1.10 Summary

2. Variation of cross-sectional structure

2.1 First variation

2.2 Second variation

3. Configuration example of imaging device

4. Application example to mobile body

5. Application example to endoscopic surgery system

1. ONE EMBODIMENT

First, a solid-state imaging device (hereinafter, referred to as animage sensor), an electronic apparatus, and a recognition systemaccording to one embodiment will be described in detail with referenceto the drawings.

Note that, in the present embodiment, a case where the technologyaccording to the present embodiment is applied to a complementarymetal-oxide semiconductor (CMOS) image sensor will be exemplified, butthe present invention is not limited to this. For example, thetechnology according to the present embodiment can be applied to varioussensors including a photoelectric conversion element, such as acharge-coupled device (CCD) image sensor, a time-of-flight (ToF) sensor,and a synchronous type or an asynchronous type event visio sensor (EVS).Note that the CMOS image sensor may be an image sensor created byapplying or partially using a CMOS process.

1.1 SYSTEM CONFIGURATION EXAMPLE

FIG. 1 is a schematic diagram depicting a schematic configurationexample of an electronic apparatus according to the present embodiment,and FIG. 2 is a block diagram depicting a schematic configurationexample of a distance measuring device using an electronic apparatusaccording to the present embodiment.

As depicted in FIG. 1 , an electronic apparatus 1 according to thepresent embodiment includes a laser light source 1010, an irradiationlens 1030, an imaging lens 1040, an image sensor 100, and a systemcontrol unit 1050.

As depicted in FIG. 2 , the laser light source 1010 includes, forexample, a vertical cavity surface emitting laser (VCSEL) 1012 and alight source driving unit 1011 that drives the VCSEL 1012. However, thepresent invention is not limited to the VCSEL 1012, and various lightsources such as a light emitting diode (LED) may be used. In addition,the laser light source 1010 may be any of a point light source, asurface light source, and a line light source. In the case of a surfacelight source or a line light source, the laser light source 1010 mayhave, for example, a configuration in which a plurality of point lightsources (for example, VCSELs) is arranged one-dimensionally ortwo-dimensionally. Note that, in the present embodiment, the laser lightsource 1010 may emit light of a wavelength band different from thewavelength band of visible light, such as infrared (IR) light, forexample.

The irradiation lens 1030 is disposed on an emission surface side of thelaser light source 1010, and converts light emitted from the laser lightsource 1010 into irradiation light having a predetermined divergenceangle.

The imaging lens 1040 is disposed on the light receiving surface side ofthe image sensor 100, and forms an image by incident light on the lightreceiving surface of the image sensor 100. The incident light can alsoinclude reflected light emitted from the laser light source 1010 andreflected by a subject 901.

As will be described in detail later, the image sensor 100 includes, forexample, a light receiving unit 1022 in which a plurality of pixels isarranged in a two-dimensional lattice shape, and a sensor control unit1021 that drives the light receiving unit 1022 to generate image data,as depicted in FIG. 2 . The pixels disposed in the light receiving unit1022 may include, for example, a pixel that detects light in awavelength band of visible light, a pixel that detects light in awavelength band other than visible light, for example, light in awavelength band of infrared light, and the like. At this time, a pixelthat detects light in a wavelength band other than visible light may bea pixel (for an image sensor) for generating image data of light in awavelength band other than visible light, a pixel (for a ToF sensor) formeasuring a distance to an object, or a pixel (for EVS) for detecting aluminance change. Hereinafter, for simplification of description, alldata read out from each pixel of the light receiving unit 1022 andgenerated is referred to as image data.

The system control unit 1050 includes, for example, a processor (CPU),and drives the VCSEL 1012 via the light source driving unit 1011. Inaddition, the system control unit 1050 acquires image data bycontrolling the image sensor 100. At that time, the system control unit1050 may acquire image data obtained by detecting reflected light ofirradiation light emitted from the laser light source 1010 bycontrolling the image sensor 100 in synchronization with control of thelaser light source 1010.

For example, the irradiation light emitted from the laser light source1010 is projected onto the subject (also referred to as a measurementtarget or an object) 901 through the irradiation lens 1030. Theprojected light is reflected by subject 901. Then, the light reflectedby the subject 901 is incident on the image sensor 100 through theimaging lens 1040. The light receiving unit 1022 in the image sensor 100receives the reflected light reflected by the subject 901 and generatesimage data. The image data generated by the image sensor 100 is suppliedto an application processor 1100 of the electronic apparatus 1. Theapplication processor 1100 can execute various types of processing suchas recognition processing and arithmetic processing on the image datainput from the image sensor 100.

1.2 CONFIGURATION EXAMPLE OF SOLID-STATE IMAGING DEVICE

FIG. 3 is a block diagram depicting a schematic configuration example ofan image sensor in the present embodiment. As depicted in FIG. 3 , theimage sensor 100 includes, for example, a pixel array section 101, avertical drive circuit 102, a signal processing circuit 103, ahorizontal drive circuit 104, a system control circuit 105, a dataprocessing unit 108, and a data storage section 109. In the followingdescription, the vertical drive circuit 102, the signal processingcircuit 103, the horizontal drive circuit 104, the system controlcircuit 105, the data processing unit 108, and the data storage section109 are also referred to as peripheral circuits.

The pixel array section 101 has a configuration in which pixels(hereinafter, referred to as a unit pixel) 110 having photoelectricconversion elements that generate and accumulate charges according tothe amount of received light are disposed in a row direction and acolumn direction, that is, in a two-dimensional lattice shape(hereinafter, also referred to as a matrix). Here, the row directionrefers to an arrangement direction of pixels in a pixel row (lateraldirection in drawings), and the column direction refers to anarrangement direction of pixels in a pixel column (longitudinaldirection in drawings).

In the pixel array section 101, a pixel drive line LD is wired along therow direction for each pixel row, and a vertical signal line VSL iswired along the column direction for each pixel column with respect tothe matrix-like pixel array. The pixel drive line LD transmits a drivesignal for driving when a signal is read out from a pixel. In FIG. 3 ,the pixel drive lines LD are depicted as wiring lines one by one, butare not limited to wiring lines one by one. One end of the pixel driveline LD is connected to an output terminal corresponding to each row ofthe vertical drive circuit 102.

The vertical drive circuit 102 includes a shift register, an addressdecoder, and the like, and drives each pixel of the pixel array section101 simultaneously for all pixels or in units of rows. That is, thevertical drive circuit 102 includes a driving unit that controls theoperation of each pixel of the pixel array section 101 together with thesystem control circuit 105 that controls the vertical drive circuit 102.Although a specific configuration of the vertical drive circuit 102 isnot depicted, the vertical drive circuit 102 generally includes twoscanning systems of a readout scanning system and a sweep scanningsystem.

In order to read out a signal from the each pixel of the unit pixel 110,the readout scanning system sequentially selects and scans each pixel ofthe unit pixel 110 of the pixel array section 101 in units of rows. Thesignal read out from each pixel of the unit pixel 110 is an analogsignal. The sweep scanning system performs sweep scanning on a read rowon which read scanning is performed by the readout scanning system priorto the readout scanning by an exposure time.

By the sweep scanning by the sweep scanning system, unnecessary chargesare swept out from the photoelectric conversion element of each pixel ofthe unit pixel 110 of the read row, and the photoelectric conversionelement is reset. Then, by sweeping out (resetting) unnecessary chargesin the sweeping scanning system, a so-called electronic shutteroperation is performed. Here, the electronic shutter operation refers toan operation of discarding charges of the photoelectric conversionelement and newly starting exposure (starting accumulation of charges).

The signal read out by the readout operation by the readout scanningsystem corresponds to the amount of light received after the immediatelypreceding readout operation or electronic shutter operation. Then, aperiod from the readout timing by the immediately preceding readoutoperation or the sweep timing by the electronic shutter operation to thereadout timing by the current readout operation is the chargeaccumulation period (exposure period) in each pixel of the unit pixel110.

The signal output from each unit pixel 110 of the pixel row selectivelyscanned by the vertical drive circuit 102 is input to the signalprocessing circuit 103 through each of the vertical signal line VSL foreach pixel column. The signal processing circuit 103 performspredetermined signal processing on the signal output from each unitpixel of the selected row through the vertical signal line VSL for eachpixel column of the pixel array section 101, and temporarily holds thepixel signal after the signal processing.

Specifically, the signal processing circuit 103 performs at least noiseremoval processing, for example, correlated double sampling (CDS)processing as signal processing and double data sampling (DDS). Forexample, by the CDS processing, fixed pattern noise unique to pixelssuch as reset noise and threshold variation of the amplificationtransistor in the pixel is removed. The signal processing circuit 103also has, for example, an analog-digital (AD) conversion function,converts an analog pixel signal read out from the photoelectricconversion element into a digital signal, and outputs the digitalsignal.

The horizontal drive circuit 104 includes a shift register, an addressdecoder, and the like, and sequentially selects a readout circuit(hereinafter, referred to as a pixel circuit) corresponding to the pixelcolumn of the signal processing circuit 103. By the selective scanningby the horizontal drive circuit 104, the pixel signals subjected to thesignal processing for each pixel circuit in the signal processingcircuit 103 are sequentially output.

The system control circuit 105 includes a timing generator thatgenerates various timing signals and the like, and performs drivecontrol of the vertical drive circuit 102, the signal processing circuit103, and the horizontal drive circuit 104 based on various timingsgenerated by the timing generator.

The data processing unit 108 has at least an arithmetic processingfunction, and performs various types of signal processing such asarithmetic processing on the pixel signal output from the signalprocessing circuit 103. The data storage section 109 temporarily storesdata necessary for signal processing in the data processing unit 108.

Note that the image data output from the data processing unit 108 may besubjected to predetermined processing in the application processor 1100and the like in the electronic apparatus 1 equipped with the imagesensor 100, or may be transmitted to the outside via a predeterminednetwork, for example.

1.3 STACKED STRUCTURE EXAMPLE OF SOLID-STATE IMAGING DEVICE

FIG. 4 is a diagram depicting a stacked structure example of the imagesensor according to the present embodiment. As depicted in FIG. 4 , theimage sensor 100 has a stack structure in which a light receiving chip121 and a circuit chip 122 are vertically stacked. The light receivingchip 121 may be, for example, a semiconductor chip including a pixelarray section 101 in which a plurality of unit pixels 110 are arrangedin a matrix, and the circuit chip 122 may be, for example, asemiconductor chip including a peripheral circuit and the like in FIG. 3.

For bonding the light receiving chip 121 and the circuit chip 122, forexample, so-called direct bonding can be used, in which the bondingsurfaces are planarized and both are bonded to each other by anelectronic force.

However, the present invention is not limited to this, and for example,so-called Cu—Cu bonding in which copper (Cu) electrode pads formed onthe bonding surfaces are bonded to each other, bump bonding, and thelike can also be used.

In addition, the light receiving chip 121 and the circuit chip 122 areelectrically connected via a connecting section such as athrough-silicon via (TSV) penetrating the semiconductor substrate, forexample. For the connection using the TSV, for example, a so-called twinTSV method in which two TSVs, that is, a TSV provided in the lightreceiving chip 121 and a TSV provided from the light receiving chip 121to the circuit chip 122 are connected by an outer surface of the chip, aso-called shared TSV method in which both are connected by a TSVpenetrating from the light receiving chip 121 to the circuit chip 122,and the like can be adopted.

However, in a case where Cu—Cu bonding or bump bonding is used forbonding the light receiving chip 121 and the circuit chip 122, both areelectrically connected via a Cu—Cu bonding portion or a bump bondingportion.

1.4 CONFIGURATION EXAMPLE OF UNIT PIXEL

Next, a configuration example of the unit pixel 110 will be described.Note that, here, a case where the unit pixel 110 includes a pixel(hereinafter, also referred to as an RGB pixel 10) that detects eachcolor component in the three primary colors of RGB and a pixel(hereinafter, also referred to as an IR pixel 20) that detects infrared(IR) light will be described as an example. Note that, in FIG. 5 and thefollowing description, in a case where color filters 31 r, 31 g, and 31b that transmit the light of the respective color componentsconstituting the three primary colors of RGB are not distinguished, thereference numeral is 31.

FIG. 5 is a schematic diagram depicting a schematic configurationexample of a pixel array section according to the present embodiment. Asdepicted in FIG. 5 , the pixel array section 101 has a configuration inwhich the unit pixels 110 having a structure in which the unit pixels110 including the RGB pixels 10 and the IR pixels 20 are arranged alongthe light incident direction are arranged in a two-dimensional latticeshape. That is, in the present embodiment, the RGB pixels 10 and the IRpixels 20 are positioned in the direction vertical to the arrangementdirection (plane direction) of the unit pixels 110, and the lighttransmitted through the RGB pixels 10 positioned on the upstream side inthe optical path of the incident light is configured to be incident onthe IR pixels 20 positioned on the downstream side of the RGB pixels 10.According to such a configuration, a photoelectric conversion sectionPD2 of the IR pixel 20 is disposed on the surface side opposite to theincident surface of the incident light in a photoelectric conversionsection PD1 of the RGB pixel 10. As a result, in the present embodiment,the optical axes of the incident light of the RGB pixel 10 and the IRpixel 20 arranged along the light incident direction coincide orsubstantially coincide with each other.

Note that, in the present embodiment, a case where the photoelectricconversion section PD1 constituting the RGB pixel 10 is made of anorganic material and the photoelectric conversion section PD2constituting the IR pixel 20 is made of a semiconductor material such assilicon is exemplified, but the present invention is not limited tothis. For example, both the photoelectric conversion section PD1 and thephotoelectric conversion section PD2 may be made of a semiconductormaterial, both the photoelectric conversion section PD1 and thephotoelectric conversion section PD2 may be made of an organic material,or the photoelectric conversion section PD1 may be made of asemiconductor material and the photoelectric conversion section PD2 maybe made of an organic material. Alternatively, at least one of thephotoelectric conversion section PD1 and the photoelectric conversionsection PD2 may be made of a photoelectric conversion material differentfrom the organic material and the semiconductor material.

1.5 CIRCUIT CONFIGURATION EXAMPLE OF UNIT PIXEL

Next, a circuit configuration example of the unit pixel 110 will bedescribed. FIG. 6 is a circuit diagram depicting a schematicconfiguration example of a unit pixel according to the presentembodiment. As depicted in FIG. 6 , in the present example, the unitpixel 110 includes one RGB pixel 10 and one IR pixel 20.

(RGB Pixel 10)

The RGB pixel 10 includes, for example, the photoelectric conversionsection PD1, a transfer gate 11, a floating diffusion region FD1, areset transistor 12, an amplification transistor 13, and a selectiontransistor 14.

A selection control line included in the pixel drive line LD isconnected to the gate of the selection transistor 14, a reset controlline included in the pixel drive line LD is connected to the gate of thereset transistor 12, and a transfer control line included in the pixeldrive line LD is connected to an accumulation electrode (see anaccumulation electrode 37 in FIG. 8 to be described later) to bedescribed later of the transfer gate 11. In addition, a vertical signalline VSL1 having one end connected to the signal processing circuit 103is connected to the drain of the amplification transistor 13 via theselection transistor 14.

In the following description, the reset transistor 12, the amplificationtransistor 13, and the selection transistor 14 are also collectivelyreferred to as a pixel circuit. The pixel circuit may include thefloating diffusion region FD1 and/or the transfer gate 11.

The photoelectric conversion section PD1 is made of, for example, anorganic material, and photoelectrically converts incident light. Thetransfer gate 11 transfers the charges generated in the photoelectricconversion section PD1. The floating diffusion region FD1 accumulatesthe charges transferred by the transfer gate 11. The amplificationtransistor 13 causes a pixel signal having a voltage value correspondingto the charges accumulated in the floating diffusion region FD1 toappear in the vertical signal line VSL1. The reset transistor 12releases the charges accumulated in the floating diffusion region FD1.The selection transistor 14 selects the RGB pixel 10 to be read out.

The anode of the photoelectric conversion section PD1 is grounded, andthe cathode is connected to the transfer gate 11. Although thephotoelectric conversion section PD1 will be described in detail laterwith reference to FIG. 8 , for example, the accumulation electrode 37 isdisposed close. At the time of exposure, a voltage for collectingcharges generated in the photoelectric conversion section PD1 to asemiconductor layer 35 near the accumulation electrode 37 is applied tothe accumulation electrode 37 via the transfer control line. At the timeof reading, a voltage for causing charges collected in the semiconductorlayer 35 near the accumulation electrode 37 to flow out through areadout electrode 36 is applied to the accumulation electrode 37 throughthe transfer control line.

The charges flowing out through the readout electrode 36 are accumulatedin the floating diffusion region FD1 including a wiring structureconnecting the readout electrode 36, the source of the reset transistor12, and the gate of the amplification transistor 13. Note that the drainof the reset transistor 12 may be connected to, for example, a powersupply voltage VDD or a power supply line to which a reset voltage lowerthan the power supply voltage VDD is supplied.

The source of the amplification transistor 13 may be connected to apower supply line via, for example, a constant current circuit (notdepicted) and the like. The drain of the amplification transistor 13 isconnected to the source of the selection transistor 14, and the drain ofthe selection transistor 14 is connected to the vertical signal lineVSL1.

The floating diffusion region FD1 converts the accumulated charges intoa voltage of a voltage value corresponding to the charge amount. Notethat the floating diffusion region FD1 may be, for example, a groundcapacity. However, the present invention is not limited to this, and thefloating diffusion region FD1 may be a capacity and the like added byintentionally connecting a capacitor and the like to a node where thedrain of the transfer gate 11, the source of the reset transistor 12,and the gate of the amplification transistor 13 are connected.

The vertical signal line VSL1 is connected to an analog-to-digital (AD)conversion circuit 103 a provided for each column (that is, for eachvertical signal line VSL1) in the signal processing circuit 103. The ADconversion circuit 103 a includes, for example, a comparator and acounter, and converts an analog pixel signal into a digital pixel signalby comparing a reference voltage such as a single slope or a ramp shapeinput from an external reference voltage generation circuit(digital-to-analog converter (DAC)) with the pixel signal appearing inthe vertical signal line VSL1. Note that the AD conversion circuit 103 amay include, for example, a correlated double sampling (CDS) circuit andthe like, and may be configured to be able to reduce kTC noise and thelike.

(IR Pixel 20)

The IR pixel 20 includes, for example, the photoelectric conversionsection PD2, a transfer transistor 21, a floating diffusion region FD2,a reset transistor 22, an amplification transistor 23, a selectiontransistor 24, and a discharge transistor 25. That is, in the IR pixel20, the transfer gate 11 in the RGB pixel 10 is replaced with thetransfer transistor 21, and the discharge transistor 25 is added.

The connection relationship among the floating diffusion region FD2, thereset transistor 22, and the amplification transistor 23 with respect tothe transfer transistor 21 may be similar to the connection relationshipamong the floating diffusion region FD1, the reset transistor 12, andthe amplification transistor 13 with respect to the transfer gate 11 inthe RGB pixel 10. In addition, the connection relationship among theamplification transistor 23, the selection transistor 24, and a verticalsignal line VSL2 may be similar to the connection relationship among theamplification transistor 13, the selection transistor 14, and thevertical signal line VSL1 in the RGB pixel 10.

The source of the transfer transistor 21 is connected to, for example,the cathode of the photoelectric conversion section PD2, and the drainis connected to the floating diffusion region FD2. In addition, thetransfer control line included in the pixel drive line LD is connectedto the gate of the transfer transistor 21.

The source of the discharge transistor 25 may be connected to, forexample, the cathode of the photoelectric conversion section PD2, andthe drain may be connected to the power supply voltage VDD or a powersupply line to which a reset voltage lower than the power supply voltageVDD is supplied. In addition, the discharge control line included in thepixel drive line LD is connected to the gate of the discharge transistor25.

In the following description, the reset transistor 22, the amplificationtransistor 23, and the selection transistor 24 are also collectivelyreferred to as a pixel circuit. The pixel circuit may include one ormore of the floating diffusion region FD2, the transfer transistor 21,and the discharge transistor 25.

The photoelectric conversion section PD2 is made of, for example, asemiconductor material, and photoelectrically converts incident light.The transfer transistor 21 transfers the charges generated in thephotoelectric conversion section PD2. The floating diffusion region FD2accumulates the charges transferred by the transfer transistor 21. Theamplification transistor 23 causes a pixel signal having a voltage valuecorresponding to the charges accumulated in the floating diffusionregion FD2 to appear in the vertical signal line VSL2. The resettransistor 22 releases the charges accumulated in the floating diffusionregion FD2. The selection transistor 24 selects the IR pixel 20 to beread out.

The anode of the photoelectric conversion section PD2 is grounded, andthe cathode is connected to the transfer transistor 21. The drain of thetransfer transistor 21 is connected to the source of the resettransistor 22 and the gate of the amplification transistor 23, and awiring structure connecting these components constitutes the floatingdiffusion region FD2. The charges flowing out from the photoelectricconversion section PD2 via the transfer transistor 21 are accumulated inthe floating diffusion region FD2.

The floating diffusion region FD2 converts the accumulated charges intoa voltage of a voltage value corresponding to the charge amount. Notethat the floating diffusion region FD2 may be, for example, a groundcapacity. However, the present invention is not limited to this, and thefloating diffusion region FD2 may be a capacity and the like added byintentionally connecting a capacitor and the like to a node where thedrain of the transfer transistor 21, the source of the reset transistor22, and the gate of the amplification transistor 23 are connected.

The discharge transistor 25 is turned on when discharging the chargesaccumulated in the photoelectric conversion section PD2 and resettingthe photoelectric conversion section PD2. As a result, the chargesaccumulated in the photoelectric conversion section PD2 flow out to thepower supply line via the discharge transistor 25, and the photoelectricconversion section PD2 is reset to an unexposed state.

Similarly to the vertical signal line VSL1, the vertical signal lineVSL2 is connected to the AD conversion circuit 103 a provided for eachcolumn (that is, for each vertical signal line VSL2) in an IR signalprocessing circuit 103B

1.5.1 MODIFICATION OF CIRCUIT CONFIGURATION

Here, a circuit configuration that enables so-called global shuttermethod readout drive for the RGB pixels 10 in the pixel array section101 will be described as a modification. FIG. 7 is a circuit diagramdepicting a schematic configuration example of a unit pixel according toa modification of the present embodiment. As depicted in FIG. 7 , in thepresent modification, an RGB pixel 10A in each unit pixel 110 furtherincludes a memory MEM and a transfer gate 15.

The memory MEM is connected to the transfer gate 11 and temporarilyholds the charges flowing out from the photoelectric conversion sectionPD1. The transfer gate 15 is provided between the memory MEM and thefloating diffusion region FD1, and suppresses leakage of charges fromthe memory MEM.

At the time of charge transfer after exposure, the transfer gates 11 ofall the RGB pixels 10 in the pixel array section 101 are simultaneouslyturned on. The ON state of the transfer gate 11 is a state configured inrelation to the accumulation electrode 37. For example, in a case wherethe charge generated in the photoelectric conversion section PD1 is anelectron, the potential of the accumulation electrode 37 is higher thanthe potential of the transfer gate. In a case where the charge is ahole, the potential of the accumulation electrode 37 is lower than thepotential of the transfer gate. Therefore, the charges accumulated inthe semiconductor layer 35 flow out to the FD1 via the transfer gate 11.On the other hand, the OFF state of the transfer gate 11 means that, forexample, in a case where the charge generated in the photoelectricconversion section PD1 is an electron, the potential of the accumulationelectrode 37 is lower than the potential of the transfer gate 11. In acase where the charge is a hole, the potential of the accumulationelectrode 37 is higher than the potential of the transfer gate.Therefore, the charges generated in a photoelectric conversion film 34are accumulated in the semiconductor layer 35. By turning on thetransfer gates 11 of all the RGB pixels 10 all at once, the chargesgenerated in the photoelectric conversion section PD1 of each RGB pixel10 during the same period are transferred to and held in the memory MEMof each RGB pixel 10. The readout of the pixel signal based on thecharges held in the memory MEM may be similar to the so-called rollingshutter type readout drive. Note that, in the following description, acase where the charges generated by photoelectric conversion by thephotoelectric conversion sections PD1 and PD2 are electrons isexemplified, but the present invention is not limited to this. Even in acase where the charges are holes, the technology according to thepresent disclosure can be similarly applied by reversing the directionof potential control.

1.6 CROSS-SECTIONAL STRUCTURE EXAMPLE OF UNIT Pixel

Next, with reference to FIG. 8 , a cross-sectional structure example ofthe image sensor 100 according to one embodiment will be described. FIG.8 is a cross-sectional diagram depicting a cross-sectional structureexample of the image sensor according to the present embodiment. Here, across-sectional structure example will be described focusing on asemiconductor chip in which the photoelectric conversion sections PD1and PD2 in the unit pixel 110 are formed.

In addition, in the following description, a so-called back surfaceirradiation type cross-sectional structure in which the light incidentsurface is on the back surface side (opposite side to the elementformation surface) of a semiconductor substrate 50 is exemplified, butthe present invention is not limited to this, and a so-called frontsurface irradiation type cross-sectional structure in which the lightincident surface is on the front surface side (element formation surfaceside) of the semiconductor substrate 50 may be used. Furthermore, in thepresent description, a case where an organic material is used for thephotoelectric conversion section PD1 of the RGB pixel 10 is exemplified,but as described above, one or both of an organic material and asemiconductor material (also referred to as an inorganic material) maybe used as the photoelectric conversion material of each of thephotoelectric conversion sections PD1 and PD2.

Note that, in a case where a semiconductor material is used for both thephotoelectric conversion material of the photoelectric conversionsection PD1 and the photoelectric conversion material of thephotoelectric conversion section PD2, the image sensor 100 may have across-sectional structure in which the photoelectric conversion sectionPD1 and the photoelectric conversion section PD2 are built in the samesemiconductor substrate 50, may have a cross-sectional structure inwhich a semiconductor substrate in which the photoelectric conversionsection PD1 is built and a semiconductor substrate in which thephotoelectric conversion section PD2 is built are bonded, or may have across-sectional structure in which one of the photoelectric conversionsections PD1 and PD2 is built in the semiconductor substrate 50 and theother is built in a semiconductor layer formed on the back surface orthe front surface of the semiconductor substrate 50.

As depicted in FIG. 8 , the present embodiment has a structure in whichthe photoelectric conversion section PD2 of the IR pixel 20 is formed onthe semiconductor substrate 50, and the photoelectric conversion sectionPD1 of the RGB pixel 10 is provided on the back surface side (oppositeside to an element formation surface) of the semiconductor substrate 50.Note that, in FIG. 8 , for convenience of description, the back surfaceof the semiconductor substrate 50 is positioned on the upper side in theplane of the drawing, and the front surface is positioned on the lowerside.

For the semiconductor substrate 50, for example, a semiconductormaterial such as silicon (Si) may be used. However, the semiconductormaterial is not limited to this, and various semiconductor materialsincluding compound semiconductors such as GaAs, InGaAs, InP, AlGaAs,InGaP, AlGaInP, and InGaAsP may be used.

(RGB Pixel 10)

The photoelectric conversion section PD1 of the RGB pixel 10 is providedon the back surface side of the semiconductor substrate 50 with aninsulating layer 53 sandwiched between. The photoelectric conversionsection PD1 includes, for example, a photoelectric conversion film 34made of an organic material, and a transparent electrode 33 and thesemiconductor layer 35 disposed to sandwich the photoelectric conversionfilm 34. The transparent electrode 33 provided on the upper side(hereinafter, the upper side in the plane of the drawing is an uppersurface side, and the lower side is a lower surface side) in the planeof the drawing with respect to the photoelectric conversion film 34functions as, for example, an anode of the photoelectric conversionsection PD1, and the semiconductor layer 35 provided on the lowersurface side functions as a cathode of the photoelectric conversionsection PD1.

The semiconductor layer 35 functioning as a cathode is electricallyconnected to the readout electrode 36 formed in an insulating layer 53.The readout electrode 36 is electrically drawn out to the front surface(lower surface) side of the semiconductor substrate 50 by beingconnected to wirings 61, 62, 63, and 64 penetrating the insulating layer53 and the semiconductor substrate 50. Note that, although not depictedin FIG. 8 , the wiring 64 is electrically connected to the floatingdiffusion region FD1 depicted in FIG. 6 .

the accumulation electrode 37 is provided on the lower surface side ofthe semiconductor layer 35 functioning as a cathode with the insulatinglayer 53 sandwiched between. Although not depicted in FIG. 8 , theaccumulation electrode 37 is connected to the transfer control line in apixel drive line LD1. As described above, at the time of exposure, avoltage for collecting charges generated in the photoelectric conversionsection PD1 to the semiconductor layer 35 near the accumulationelectrode 37 is applied, and at the time of readout, a voltage forcausing charges collected in the semiconductor layer 35 near theaccumulation electrode 37 to flow out via the readout electrode 36 isapplied.

Similarly to the transparent electrode 33, the readout electrode 36 andthe accumulation electrode 37 may be transparent conductive films. Forexample, a transparent conductive film such as indium tin oxide (ITO) orzinc oxide (IZO) may be used for the transparent electrode 33, thereadout electrode 36, and the accumulation electrode 37. However, thepresent invention is not limited to this, and various conductive filmsmay be used as long as the photoelectric conversion section PD2 is aconductive film capable of transmitting light in a wavelength band to bedetected.

In addition, for the semiconductor layer 35, for example, a transparentsemiconductor layer such as IGZO may be used. However, the presentinvention is not limited to this, and various semiconductor layers maybe used as long as the photoelectric conversion section PD2 is asemiconductor layer capable of transmitting light in a wavelength bandto be detected.

Furthermore, as the insulating layer 53, for example, an insulating filmsuch as a silicon oxide film (SiO₂) or a silicon nitride film (SiN) maybe used. However, the present invention is not limited to this, andvarious insulating films may be used as long as the photoelectricconversion section PD2 is an insulating film capable of transmittinglight in a wavelength band to be detected.

A color filter 31 is provided on the upper surface side of thetransparent electrode 33 functioning as an anode with a sealing film 32sandwiched between. The sealing film 32 is made of, for example, aninsulating material such as silicon nitride (SiN), and may include atomsof aluminum (Al), titanium (Ti), and the like in order to prevent theatoms from diffusing from the transparent electrode 33.

Although the arrangement of the color filters 31 will be describedlater, for example, a color filter 31 that selectively transmits lightof a specific wavelength component is provided for one RGB pixel 10.However, in a case where a monochrome pixel that acquires luminanceinformation is provided instead of the RGB pixel 10 that acquires colorinformation, the color filter 31 may be omitted.

(IR Pixel 20)

The photoelectric conversion section PD2 of the IR pixel 20 includes,for example, a p-type semiconductor region 43 formed in a p-well region42 in the semiconductor substrate 50 and an n-type semiconductor region44 formed in the vicinity of the center of the p-type semiconductorregion 43. The n-type semiconductor region 44 functions as, for example,a charge accumulation region that accumulates charges (electrons)generated by photoelectric conversion, and the p-type semiconductorregion 43 functions as a region that forms a potential gradient forcollecting the charges generated by photoelectric conversion into then-type semiconductor region 44.

For example, an IR filter 41 that selectively transmits IR light isdisposed on the light incident surface side of the photoelectricconversion section PD2. The IR filter 41 may be disposed, for example,in the insulating layer 53 provided on the back surface side of thesemiconductor substrate 50. By disposing the IR filter 41 on the lightincident surface of the photoelectric conversion section PD2, it ispossible to suppress the incidence of visible light on the photoelectricconversion section PD2, and thus, it is possible to improve the S/Nratio of IR light to visible light. This makes it possible to obtain amore accurate detection result of IR light.

For example, a fine uneven structure is provided on the light incidentsurface of the semiconductor substrate 50 in order to suppressreflection of incident light (IR light in this example). This unevenstructure may be a structure called a moth-eye structure, or may be anuneven structure having a size and a pitch different from those of themoth-eye structure.

A longitudinal transistor 45 functioning as the transfer transistor 21is provided on the front surface (lower surface in the plane of thedrawing) side of the semiconductor substrate 50, that is, the elementformation surface side. The gate electrode of the longitudinaltransistor 45 reaches the n-type semiconductor region 44 from thesurface of the semiconductor substrate 50, and is connected to thevertical drive circuit 102 via wirings 65 and 66 (a part of the transfercontrol line of a pixel drive line LD2) formed in an interlayerinsulating film 56.

The charges flowing out via the longitudinal transistor 45 areaccumulated in the floating diffusion region FD2. The floating diffusionregion FD2 is connected to the source of the reset transistor 22 and thegate of the amplification transistor 23 via wirings (not depicted)formed in the interlayer insulating film 56. Note that the floatingdiffusion region FD2, the reset transistor 22, the amplificationtransistor 23, and the selection transistor 24 may be provided on theelement formation surface of the semiconductor substrate 50, or may beprovided on a semiconductor substrate different from the semiconductorsubstrate 50.

Note that, in the present description, a case where the RGB pixels 10positioned upstream with respect to the incident light generate the RGBimage signal, and the IR pixels 20 positioned downstream generate theimage signal based on the IR light has been exemplified, but the presentinvention is not limited to such a configuration. For example, an imagesignal based on light having a wavelength component corresponding togreen may be generated in an upstream side pixel (corresponding to theRGB pixel 10), and an image signal based on light having a wavelengthcomponent corresponding to red and an image signal based on light havinga wavelength component corresponding to blue may be generated in adownstream side pixel (corresponding to the IR pixel 20). In this case,a material that selectively absorbs a wavelength component correspondingto green is used for the photoelectric conversion film 34, and insteadof the IR filter 41, a color filter that selectively transmits awavelength component corresponding to red and a color filter thatselectively transmits a wavelength component corresponding to blue canbe arranged in a matrix. Furthermore, in this configuration, the colorfilter 31 can be omitted. With this configuration, the light receivingarea of the pixel that detects the wavelength component of each of thethree primary colors of RGB (which may be the three primary colors ofCMY and the like) constituting the color image can be expanded, in amanner that the S/N ratio can be improved due to an increase in quantumefficiency.

(Pixel Isolation Structure)

The semiconductor substrate 50 is provided with a pixel isolationsection 54 that electrically isolates the plurality of unit pixels 110from each other, and the photoelectric conversion section PD2 isprovided in each region partitioned by the pixel isolation section 54.For example, in a case where the image sensor 100 is viewed from theback surface (upper surface in the drawing) side of the semiconductorsubstrate 50, the pixel isolation section 54 has, for example, a latticeshape interposed between the plurality of unit pixels 110, and eachphotoelectric conversion section PD2 is formed in each regionpartitioned by the pixel isolation section 54.

For the pixel isolation section 54, for example, a reflection film thatreflects light such as tungsten (W) or aluminum (Al) may be used. As aresult, the incident light entering the photoelectric conversion sectionPD2 can be reflected by the pixel isolation section 54, in a manner thatthe optical path length of the incident light in the photoelectricconversion section PD2 can be increased. In addition, since the pixelisolation section 54 has a light reflection structure, it is possible toreduce leakage of light to adjacent pixels, and thus, it is alsopossible to further improve image quality, distance measurementaccuracy, and the like. Note that the configuration in which the pixelisolation section 54 has the light reflection structure is not limitedto the configuration using the reflection film, and can be realized, forexample, by using a material having a refractive index different fromthat of the semiconductor substrate 50 for the pixel isolation section54.

For example, a fixed charge film 55 is provided between thesemiconductor substrate 50 and the pixel isolation section 54. The fixedcharge film 55 is formed using, for example, a high dielectric having anegative fixed charge in a manner that a positive charge (hole)accumulation region is formed at an interface portion with thesemiconductor substrate 50 and generation of a dark current issuppressed. Since the fixed charge film 55 is formed to have a negativefixed charge, an electric field is applied to the interface with asemiconductor substrate 138 by the negative fixed charge, and a positivecharge (hole) accumulation region is formed.

The fixed charge film 55 can be formed of, for example, a hafnium oxidefilm (HfO₂ film). In addition, the fixed charge film 55 can be formed tocontain at least one of oxides such as hafnium, zirconium, aluminum,tantalum, titanium, magnesium, yttrium, and lanthanoid elements, forexample.

Note that FIG. 8 depicts a case where the pixel isolation section 54 hasa so-called full trench isolation (FTI) structure reaching from thefront surface to the back surface of the semiconductor substrate 50, butis not limited to this. For example, various element isolationstructures such as a so-called deep trench isolation (DTI) structure inwhich the pixel isolation section 54 is formed from the back surface orthe front surface of the semiconductor substrate 50 to the vicinity ofthe middle of the semiconductor substrate 50 can be adopted.

(Pupil Correction)

A planarization film 52 made of a silicon oxide film, a silicon nitridefilm, and the like is provided on the upper surface of the color filter31. The upper surface of the planarization film 52 is planarized by, forexample, chemical mechanical polishing (CMP), and an on-chip lens 51 foreach unit pixel 110 is provided on the planarized upper surface. Theon-chip lens 51 of each unit pixel 110 has such a curvature thatincident light is collected in the photoelectric conversion sections PD1and PD2. Note that the positional relationship among the on-chip lens51, the color filter 31, the IR filter 41, and the photoelectricconversion section PD2 in each unit pixel 110 may be adjusted accordingto, for example, the distance (image height) from the center of thepixel array section 101 (pupil correction).

In addition, in the structure depicted in FIG. 8 , a light shieldingfilm for preventing obliquely incident light from leaking into theadjacent pixel may be provided. The light shielding film can bepositioned above the pixel isolation section 54 provided inside thesemiconductor substrate 50 (upstream side in the optical path of theincident light). However, in a case where pupil correction is performed,the position of the light shielding film may be adjusted according to,for example, the distance (image height) from the center of the pixelarray section 101. Such a light shielding film may be provided, forexample, in the sealing film 32 or the planarization film 52. Inaddition, as a material of the light shielding film, for example, alight shielding material such as aluminum (Al) or tungsten (W) may beused.

1.7 MATERIAL OF EACH LAYER

In one embodiment, in a case where an organic semiconductor is used asthe material of the photoelectric conversion film 34, the layerstructure of the photoelectric conversion film 34 can have the followingstructure. However, in the case of the stacked structure, the stackingorder can be appropriately changed.

(1) Single-layer structure of p-type organic semiconductor

(2) Single-layer structure of n-type organic semiconductor

(3-1) Stacked structure of p-type organic semiconductor layer/n-typeorganic semiconductor layer

(3-2) Stacked structure of p-type organic semiconductor layer/mixedlayer (bulk heterostructure) of p-type organic semiconductor and n-typeorganic semiconductor/n-type organic semiconductor layer

(3-3) Stacked structure of p-type organic semiconductor layer/mixedlayer (bulk heterostructure) of p-type organic semiconductor and n-typeorganic semiconductor

(3-4) Stacked structure of n-type organic semiconductor layer/mixedlayer (bulk heterostructure) of p-type organic semiconductor and n-typeorganic semiconductor

(4) Mixed layer of p-type organic semiconductor and p-type organicsemiconductor (bulk heterostructure)

Here, examples of the p-type organic semiconductor include a naphthalenederivative, an anthracene derivative, a phenanthrene derivative, apyrene derivative, a perylene derivative, a tetracene derivative, apentacene derivative, a quinacridone derivative, a thiophene derivative,a thienothiophene derivative, a benzothiophene derivative, abenzothienobenzothiophene derivative, a triallylamine derivative, acarbazole derivative, a perylene derivative, a picene derivative, achrysene derivative, a fluoranthene derivative, a phthalocyaninederivative, a subphthalocyanine derivative, a subporphyrazinederivative, a metal complex having a heterocyclic compound as a ligand,a polythiophene derivative, a polybenzothiadiazole derivative, apolyfluorene derivative, and the like.

Examples of the n-type organic semiconductor include fullerene and afullerene derivative <for example, fullerene such as C60, C70, and C74(higher fullerenes, endohedral fullerenes, etc.), or a fullerenederivative (for example, fullerene fluoride, PCBM fullerene compound,fullerene multimer, and the like)>, an organic semiconductor having alarger (deeper) HOMO and LUMO than a p-type organic semiconductor, and atransparent inorganic metal oxide.

Specific examples of the n-type organic semiconductor include an organicmolecule, an organometallic complex, and a subphthalocyanine derivativehaving a part of the molecular skeleton containing heterocycliccompounds containing a nitrogen atom, an oxygen atom, and a sulfur atom,such as pyridine derivatives, pyrazine derivatives, pyrimidinederivatives, triazine derivatives, quinoline derivatives, quinoxalinederivatives, isoquinoline derivatives, acridine derivatives, phenazinederivatives, phenanthroline derivatives, tetrazole derivatives, pyrazolederivatives, imidazole derivatives, thiazole derivatives, oxazolederivatives, imidazole derivatives, benzimidazole derivatives,benzotriazole derivatives, benzoxazole derivatives, benzoxazolederivatives, carbazole derivatives, benzofuran derivatives, dibenzofuranderivatives, subporphyrazine derivatives, polyphenylenevinylenederivatives, polybenzothiadiazole derivatives, and polyfluorenederivatives.

Halogen atom as group and the like contained in fullerene derivative,the following derivatives can be mentioned: linear, branched, or cyclicalkyl or phenyl group; group having linear or condensed aromaticcompound; group having halide; partial fluoroalkyl group; perfluoroalkylgroup; silylalkyl group; silyl alkoxy group; arylsilyl group;arylsulfanyl group; alkylsulfanyl group; arylsulfonyl group;alkylsulfonyl group; aryl sulfide group; alkyl sulfide group; aminogroup; alkylamino group; arylamino group; hydroxy group; alkoxy group;acylamino group; acyloxy group; carbonyl group; carboxy group;carboxamide group; carboalkoxy group; acyl group; sulfonyl group; cyanogroup; nitro group; group having chalcogenide; phosphine group; andphosphon group.

The film thickness of the photoelectric conversion film 34 made of theorganic material as described above is not limited to the followingvalue, but may be, for example, 1×10⁻⁸ m (meter) to 5×10⁻⁷ m, preferably2.5×10⁻⁸ m to 3×10⁻⁷ m, more preferably 2.5×10⁻⁸ m to 2×10⁻⁷ m, andstill more preferably 1×10⁻⁷ m to 1.8×10⁻⁷ m. Note that the organicsemiconductor is often classified into a p-type and an n-type, but thep-type means that holes are easily transported, and the n-type meansthat electrons are easily transported, and the organic semiconductor isnot limited to the interpretation that it has holes or electrons as amajority carrier of thermal excitation like the inorganic semiconductor.

Examples of a material constituting the photoelectric conversion film 34that photoelectrically converts light having a green wavelength includea rhodamine dye, a melacyanine dye, a quinacridone derivative, and asubphthalocyanine dye (subphthalocyanine derivative).

In addition, examples of a material constituting the photoelectricconversion film 34 that photoelectrically converts blue light include acoumaric acid dye, tris-8-hydroxyquinoline aluminum (Alq3), amelacyanine dye, and the like.

Furthermore, examples of a material constituting the photoelectricconversion film 34 that photoelectrically converts red light include aphthalocyanine dye and a subphthalocyanine dye (subphthalocyaninederivative).

Furthermore, as the photoelectric conversion film 34, a panchromaticphotosensitive organic photoelectric conversion film that is sensitiveto substantially all visible light from the ultraviolet region to thered region can be used.

On the other hand, as the material constituting the semiconductor layer35, a material having a large band gap value (for example, a value of aband gap of 3.0 eV (electron volt) or more) and having higher mobilitythan the material constituting the photoelectric conversion film 34 ispreferably used. Specific examples include oxide semiconductor materialssuch as IGZO, transition metal dichalcogenides, silicon carbides,diamond, graphene, carbon nanotubes, and organic semiconductor materialssuch as fused polycyclic hydrocarbon compounds and fused heterocycliccompounds.

Alternatively, in a case where the charges generated in thephotoelectric conversion film 34 are electrons, a material having anionization potential larger than the ionization potential of thematerial constituting the photoelectric conversion film 34 can be usedas the material constituting the semiconductor layer 35. On the otherhand, in a case where the charge is a hole, a material having anelectron affinity smaller than the electron affinity of the materialconstituting the photoelectric conversion film 34 can be used as thematerial constituting the semiconductor layer 35.

Note that the impurity concentration in the material constituting thesemiconductor layer 35 is preferably 1×10¹⁸ cm⁻³ or less. In addition,the photoelectric conversion film 34 and the semiconductor layer 35 canbe made of the same material as long as the photoelectric conversionperformance and the mobility performance can be satisfied.

Furthermore, a transparent material is desirably used as a material ofeach of the transparent electrode 33, the readout electrode 36, thesemiconductor layer 35, and the accumulation electrode 37. Specifically,a material made of Al—Nd (alloy of aluminum and neodymium) or ASC (alloyof aluminum, samarium, and copper) can be used.

In addition, the band gap energy of the transparent conductive materialis desirably 2.5 eV or more, and preferably 3.1 eV or more.

On the other hand, in a case where the transparent electrode 33, thereadout electrode 36, and the accumulation electrode 37 are transparentelectrodes, examples of the transparent conductive material constitutingthem include conductive metal oxides.

Specifically, indium oxide, indium-tin oxide (indium tin oxide (ITO),Sn-doped In₂O₃, crystalline ITO, and amorphous ITO are included),indium-zinc oxide (IZO) obtained by adding indium as a dopant to zincoxide, indium-gallium oxide (IGO) obtained by adding indium as a dopantto gallium oxide, indium-gallium-zinc oxide (IGZO (In—GaZnO₄)) obtainedby adding indium and gallium as dopants to zinc oxide, indium-tin-zincoxide (ITZO) obtained by adding indium and tin as dopants to zinc oxide,IFO (F-doped In₂O₃), tin oxide (SnO₂), ATO (Sb-doped SnO₂), FTO (F-dopedSnO₂), zinc oxide (including ZnO doped with other elements),aluminum-zinc oxide (AZO) obtained by adding aluminum as a dopant tozinc oxide, gallium-zinc oxide (GZO) obtained by adding gallium as adopant to zinc oxide, titanium oxide (TiO₂), niobium-titanium oxide(TNO) obtained by adding niobium as a dopant to titanium oxide, antimonyoxide, spinel type oxide, and oxide having a YbFe₂O₄ structure can beexemplified.

Alternatively, a transparent electrode using gallium oxide, titaniumoxide, niobium oxide, nickel oxide, and the like as a parent layer canalso be exemplified.

Furthermore, the thickness of the transparent electrode may be 2×10⁻⁸ mto 2×10⁻⁷ m, preferably 3×10⁻⁸ m to 1×10⁻⁷ m.

1.8 MODIFICATION OF UNIT PIXEL

In the above description, the case where one unit pixel includes one RGBpixel 10 and one IR pixel 20 has been exemplified, but the presentinvention is not limited to such a configuration. That is, each unitpixel 110 may include N (N is an integer of 1 or more) RGB pixels 10 andM (M is an integer of 1 or more) IR pixels 20. In this case, the N RGBpixels 10 may share a part of the pixel circuit, and similarly, the M IRpixels 20 may share a part of the pixel circuit.

1.8.1 CONFIGURATION EXAMPLE OF UNIT PIXEL

FIG. 9 is a schematic diagram depicting a schematic configurationexample of a unit pixel according to a modification of the presentembodiment. As depicted in FIG. 9 , a unit pixel 110A has a structure inwhich one IR pixel 20 is disposed in the light incident direction withrespect to four RGB pixels 10 arranged in two rows and two columns. Thatis, in the present modification, one IR pixel 20 for four RGB pixels 10positioned in the direction vertical to the arrangement direction (planedirection) of the unit pixels 110A, and the light transmitted throughfour RGB pixels 10 positioned on the upstream side in the optical pathof the incident light is configured to be incident on one IR pixel 20positioned on the downstream side of four RGB pixels 10. Therefore, inthe present modification, the optical axes of the incident light of theunit array of the Bayer array including four RGB pixels 10 and the IRpixel 20 coincide or substantially coincide with each other.

1.8.2 CIRCUIT CONFIGURATION EXAMPLE OF UNIT PIXEL

FIG. 10 is a circuit diagram depicting a schematic configuration exampleof a unit pixel according to a modification of the present embodiment.As depicted in FIG. 10 , the unit pixel 110A includes the plurality ofRGB pixels 10-1 to 10-N (in FIG. 10 , N is 4) and one IR pixel 20. Asdescribed above, in a case where one unit pixel 110A includes theplurality of RGB pixels 10, one pixel circuit (reset transistor 12,floating diffusion region FD1, amplification transistor 13, andselection transistor 14) can be shared by the plurality of RGB pixels 10(pixel sharing). Therefore, in the present modification, the pluralityof RGB pixels 10-1 to 10-N shares a pixel circuit including the resettransistor 12, the floating diffusion region FD1, the amplificationtransistor 13, and the selection transistor 14. That is, in the presentmodification, the plurality of photoelectric conversion sections PD1 andthe transfer gate 11 are connected to the common floating diffusionregion FD1.

1.8.3 CROSS-SECTIONAL STRUCTURE EXAMPLE OF UNIT PIXEL

FIG. 11 is a cross-sectional diagram depicting a cross-sectionalstructure example of an image sensor according to a modification of thepresent embodiment. Note that, in the present description, similarly toFIG. 8 , a case where each unit pixel 110A includes four RGB pixels 10arranged in two rows and two columns and one IR pixel 20 will bedescribed as an example. In addition, in the following description,similarly to FIG. 8 , a cross-sectional structure example will bedescribed focusing on a semiconductor chip in which the photoelectricconversion sections PD1 and PD2 in the unit pixel 110A are formed.Furthermore, in the following description, structures similar to thecross-sectional structure of the image sensor 100 described withreference to FIG. 8 are cited, and redundant description is omitted.

As depicted in FIG. 11 , in the present modification, in across-sectional structure similar to the cross-sectional structuredepicted in FIG. 8 , the on-chip lens 51, the color filter 31, and theaccumulation electrode 37 are divided into four in two rows and twocolumns (however, two out of four are depicted in FIG. 11 .),configuring four RGB pixels 10. Note that the four RGB pixels 10 in eachunit pixel 210 may constitute a basic array of the Bayer array.

1.9 IMPROVEMENT OF QUANTUM EFFICIENCY

Subsequently, in the unit pixel 110 (or the unit pixel 110A, and thesame applies hereinafter) having the basic configuration as describedabove, a configuration for increasing the quantum efficiency will bedescribed with some examples. Note that, in the following, forclarification, attention is paid to a pixel in which the photoelectricconversion section includes an organic photoelectric conversion film (inthis example, the RGB pixel 10), and illustration and description of thepixel in which the photoelectric conversion section includes asemiconductor (in the present example, the IR pixel 20) are omitted. Inaddition, in order to simplify the description, in the cross-sectionalstructure of the RGB pixel 10, a configuration above the color filter 31and a configuration below the readout electrode 36 will not be depictedand described. Furthermore, in the following description, the RGB pixel10 is also simply referred to as a pixel 10. Furthermore, in thefollowing description, the readout electrode 36 electrically connectedto the floating diffusion region FD1 will be described as a part of thefloating diffusion region FD1. Furthermore, in the followingdescription, a case where the charge generated by photoelectricconversion of the photoelectric conversion film 34 is a negative charge(that is, electrons) will be exemplified. However, the charge generatedby the photoelectric conversion of the photoelectric conversion film 34may be a positive charge (that is, a hole). Furthermore, the structureand effect described in each example may be similar to other examples ifnot specifically mentioned.

1.9.1 FIRST EXAMPLE

FIG. 12 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the first example ofthe present embodiment. FIG. 13 is a horizontal cross-sectional diagramdepicting an A-A cross section in FIG. 12 . Note that, here, the term“vertical” means vertical to the element formation surface of thesemiconductor substrate 50, and the term “horizontal” means horizontalto the element formation surface.

As depicted in FIGS. 12 and 13 , in the pixel 10 according to the firstexample, a part of the semiconductor layer 35 positioned immediatelybelow the photoelectric conversion film 34 protrudes to the oppositeside to the photoelectric conversion film 34 and is connected to thereadout electrode 36. In the following description, this protrudingportion is referred to as a semiconductor wiring 60.

On the side of the semiconductor layer 35 of the semiconductor wiring60, the accumulation electrode 37 having the center is opened isdisposed to surround the semiconductor wiring 60. The accumulationelectrode 37 and the semiconductor wiring 60 are electrically isolatedfrom each other with the insulating layer 53 interposed between.

In addition, the transfer gate 11 is disposed on the side of the readoutelectrode 36 of the semiconductor wiring 60. The transfer gate 11includes, for example, a fixed charge film having the same polarity asthe charges generated in the photoelectric conversion film 34. Similarlyto the fixed charge film 55, the material of the fixed charge film canbe formed to contain a hafnium oxide film (HfO₂ film) or at least one ofoxides such as hafnium, zirconium, aluminum, tantalum, titanium,magnesium, yttrium, and lanthanoid elements, for example. The potentialof the fixed charge film, that is, the transfer gate 11 is desirablylower than the potential of the semiconductor layer 35 near theaccumulation electrode 37 when the accumulation electrode 37 is turnedoff. Similarly to the accumulation electrode 37, such transfer gate 11has a shape having the center is opened, and is disposed to surround thesemiconductor wiring 60. The transfer gate 11 and the semiconductorwiring 60 may be separated or in contact with each other via theinsulating layer 53.

Note that, in a case where the unit pixel 110 has a pixel sharingconfiguration that shares a part of the pixel circuit as depicted inFIG. 11 , the accumulation electrode 37 and the transfer gate 11disposed with respect to the semiconductor wiring 60 may be divided foreach pixel 10.

In such a structure, a drive signal (also referred to as a controlvoltage) for lowering the potential in the semiconductor layer 35 nearthe accumulation electrode 37 is applied from the vertical drive circuit102 to the accumulation electrode 37 during the exposure period.Therefore, charges 58 generated in the photoelectric conversion film 34and entering the semiconductor layer 35 are accumulated in a region nearthe accumulation electrode 37 in the semiconductor layer 35. At thattime, since a potential barrier is formed in the semiconductor wiring 60between the region where the charges are accumulated and the transfergate 11 by the transfer gate 11 having the same polarity as the charges,leakage of the accumulated charges to the side of the readout electrode36 is suppressed. This makes it possible to improve the quantumefficiency.

In addition, in the first example, a shield electrode (ASE) 57 isdisposed to surround the periphery of the accumulation electrode (SLD)37 of each pixel 10. The shield electrode 57 is connected to thevertical drive circuit 102 via a wiring (not depicted) which is one ofthe pixel drive lines LD. In a case where each pixel 10 is individuallydriven, the vertical drive circuit 102 applies a drive signal to theshield electrode 57 to form a potential barrier in the semiconductorlayer 35 positioned between the adjacent pixels 10. As a result, sincethe charges generated in the photoelectric conversion film 34 of acertain pixel 10 and entering the semiconductor layer 35 are suppressedfrom flowing out to the adjacent pixel 10, the quantum efficiency of thepixel 10 can be further improved.

Note that, in FIG. 13 , a case where the horizontal cross section of thesemiconductor wiring 60 and the opening shape of the accumulationelectrode 37 and the transfer gate 11 are circular has been exemplified.However, for example, as depicted in FIGS. 14 and 15 , the horizontalcross section and the opening shape may be changed to various shapessuch as a polygon such as a quadrangle and a regular octagon and anellipse. The same applies to other examples to be described later.

1.9.2 SECOND EXAMPLE

FIG. 16 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the second example ofthe present embodiment. As depicted in FIG. 16 , the pixel 10 accordingto the second example has a structure in which the transfer gate 11 isdisposed inside the accumulation electrode 37 in a cross-sectionalstructure similar to that of the pixel 10 according to the first exampledescribed above with reference to FIG. 12 . That is, in the secondexample, the opening of the accumulation electrode 37 is enlarged indiameter, and the transfer gate 11 is disposed on the same surface asthe accumulation electrode 37.

According to such a structure, since the length of the semiconductorwiring 60 can be shortened, the height of the image sensor 100 can bereduced, and the size of the image sensor can be reduced.

1.9.3 THIRD EXAMPLE

FIG. 17 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the third example ofthe present embodiment. As depicted in FIG. 17 , the pixel 10 accordingto the third example has a tapered shape in which the semiconductorwiring 60 becomes thinner toward the readout electrode 36 in across-sectional structure similar to that of the pixel 10 according tothe first example described above with reference to FIG. 12 .

According to such a structure, since the diameter of the semiconductorwiring 60 on the side of the semiconductor layer 35 is increased, thecharges accumulated in the semiconductor layer 35 can be smoothlytransferred to the side of the readout electrode 36.

In addition, since the diameter of the semiconductor wiring 60 on theside of the readout electrode 36 is reduced, the contact area with thereadout electrode 36 is reduced, in a manner that the readout electrode36 can be reduced. As a result, it is possible to increase the amount oflight propagating to the layer below the readout electrode 36, and thus,for example, it is possible to further increase the quantum efficiencyof the IR pixel 20 in a case where the photoelectric conversion sectionPD2 of the IR pixel 20 is disposed below the pixel 10.

1.9.4 FOURTH EXAMPLE

FIG. 18 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the fourth example ofthe present embodiment. As depicted in FIG. 18 , the pixel 10 accordingto the fourth example has a structure in which the readout electrode 36(and the floating diffusion region FD) is shared between adjacent pixels10 in a cross-sectional structure similar to that of the pixel 10according to the first example described above with reference to FIG. 12.

As described above, according to the structure in which the readoutelectrode 36 and the floating diffusion region FD are shared and thetransfer of the charges from each pixel 10 to the floating diffusionregion FD can be controlled using the transfer gate 11, it is possibleto switch between reading for each pixel 10 and simultaneous readingfrom the plurality of pixels 10.

1.9.5 FIFTH EXAMPLE

FIG. 19 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the fifth example ofthe present embodiment. FIG. 20 is a horizontal cross-sectional diagramdepicting a B-B cross section in FIG. 19 . Note that FIG. 19 depicts aconfiguration above the color filter 31 for convenience of description.

As depicted in FIGS. 19 and 20 , the pixel 10 according to the fifthexample has a structure in which one on-chip lens 51 is provided for aplurality of (two in this example) pixels 10 in a cross-sectionalstructure similar to that of the pixel 10 according to the first exampledescribed above with reference to FIG. 12 .

According to such a structure, it is possible to acquire the image-planephase difference information between the pixels 10 sharing one on-chiplens 51, and thus, it is possible to execute control such as autofocusbased on the image-plane phase difference information in the systemcontrol unit 1050 that controls the image sensor 100.

1.9.6 SIXTH EXAMPLE

In the sixth example, the pixel 10 capable of readout drive by theglobal shutter method depicted in FIG. 7 will be described. FIG. 21 is avertical cross-sectional diagram depicting a cross-sectional structureof a pixel according to the sixth example of the present embodiment. Asdepicted in FIG. 21 , the pixel 10 according to the sixth example has astructure in which a memory electrode 16 and the transfer gate 15constituting the memory MEM are sequentially disposed between thetransfer gate 11 and the readout electrode 36 in a cross-sectionalstructure similar to that of the pixel 10 according to the first exampledescribed above with reference to FIG. 12 .

Similarly to the transfer gate 11, for example, the transfer gate 15includes a fixed charge film, and is disposed on the side of thesemiconductor wiring 60 closest to the readout electrode 36. However,the potential of the transfer gate 15 may be a potential lower than thepotential of the transfer gate 11. Similarly to the accumulationelectrode 37, the transfer gate 15 has a shape having the center isopened, and is disposed to surround the semiconductor wiring 60. Thetransfer gate 15 and the semiconductor wiring 60 may be separated or incontact with each other via the insulating layer 53.

The memory electrode 16 is disposed between the transfer gate 11 and thetransfer gate 15. In addition, similarly to the accumulation electrode37, the memory electrode 16 has a shape having the center is opened, andis disposed to surround the semiconductor wiring 60.

According to such a structure, the charges transferred from thesemiconductor layer 35 via the transfer gate 11 can be temporarily heldin the region near the memory electrode 16 in the semiconductor wiring60. As a result, global shutter method readout drive becomes possible.

1.9.7 SEVENTH EXAMPLE

In the seventh example, the wiring example in the pixel 10 capable ofreadout drive by the global shutter method described in the sixthexample will be described. FIG. 22 is a vertical cross-sectional diagramdepicting a cross-sectional structure of a pixel according to theseventh example of the present embodiment. FIG. 23 is a horizontalcross-sectional diagram depicting a C-C cross section in FIG. 22 .

In the case of the global shutter method readout drive, the transfergates 11, that is, the accumulation electrodes 37 in all the pixels 10are simultaneously driven. Therefore, as depicted in FIGS. 22 and 23 ,the accumulation electrodes 37 of all the pixels 10 in the pixel arraysection 101 may be coupled by wirings 73. Similarly, the memoryelectrodes 16 of all the pixels 10 in the pixel array section 101 mayalso be coupled by the wirings 72.

1.9.8 EIGHTH EXAMPLE

In the eighth example, another cross-sectional structure example of thepixel 10 capable of readout drive of the global shutter method will bedescribed. FIG. 24 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the eighth example ofthe present embodiment.

As depicted in FIG. 24 , the pixel 10 according to the eighth examplehas a structure in which the semiconductor layer 35 is divided into twolayers of a first semiconductor layer 35A and a second semiconductorlayer 35B in a cross-sectional structure similar to that of the pixel 10according to the sixth example described above with reference to FIG. 21. The insulating layer 53 is interposed between the first semiconductorlayer 35A and the second semiconductor layer 35B. The semiconductorwiring 60 penetrates through the first semiconductor layer 35A to thesecond semiconductor layer 35B and reaches the readout electrode 36.

Similarly to the sixth example, the accumulation electrode 37, thetransfer gate 11, and the shield electrode 57 are disposed in theinsulating layer 53 between the first semiconductor layer 35A and thesecond semiconductor layer 35B. On the other hand, the memory electrode16 and the transfer gate 15 are disposed in the insulating layer 53between the second semiconductor layer 35B and the readout electrode 36.More specifically, the memory electrode 16 is disposed on the side ofthe second semiconductor layer 35B in the semiconductor wiring 60between the second semiconductor layer 35B and the readout electrode 36,and the transfer gate 15 is disposed on the side of the readoutelectrode 36 in the semiconductor wiring 60 between the secondsemiconductor layer 35B and the readout electrode 36.

In addition, in the eighth example, in order to suppress the chargesheld in the region near the memory electrode 16 in the secondsemiconductor layer 35B from flowing out to the adjacent pixel 10, ashield electrode 57B similar to the shield electrode 57 is providedbetween the memory electrodes 16 of the adjacent pixels 10. The shieldelectrode 57B is connected to the vertical drive circuit 102 via awiring (not depicted) which is one of the pixel drive lines LD. In acase where each pixel 10 is individually driven, the vertical drivecircuit 102 applies a drive signal to the shield electrode 57 to form apotential barrier in the second semiconductor layer 35B positionedbetween the adjacent pixels 10. As a result, since the charges held inthe memory MEM of a certain pixel 10 are suppressed from flowing out tothe memory MEM of the adjacent pixel 10, the quantum efficiency of thepixel 10 can be further improved.

1.9.9 NINTH EXAMPLE

In the ninth example, a drive example of the global shutter method willbe described. Note that, in the present example, a drive example of thepixel 10 described in the sixth example with reference to FIG. 21 willbe described, but the present invention is not limited to this, and canbe similarly applied to other examples in which global shutter methoddrive (hereinafter, referred to as global shutter drive) is possible.

FIG. 25 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the ninth example ofthe present embodiment. As depicted in FIG. 25 , in the global shutterdrive according to the ninth example, the exposure operation is notexecuted in the other pixel 10 while one pixel 10 of two adjacent pixels10 a and 10 b executes the exposure operation. Note that each of the twopixels 10 a and 10 b may have a configuration similar to that of thepixel 10 described above.

Specifically, for example, while the pixel 10 b is executing theexposure operation, the accumulation electrode 37 of the pixel 10 b isturned on, and the accumulation electrode 37 of the pixel 10 a is turnedoff. In addition, the shield electrode 57 positioned between the twopixels 10 a and 10 b is turned off. In this state, the transfer gate 11and the transfer gate 15 of the pixel 10 a, and the transfer gate 11,the memory electrode 16, and the transfer gate 15 of the pixel 10 b areturned off. In addition, the memory electrode 16 of the pixel 10 a isturned on. Note that the ON state of the accumulation electrode 37, theshield electrode 57, and the memory electrode 16 refers to a state inwhich a drive signal is supplied from the vertical drive circuit 102 toeach electrode, and the OFF state refers to a state in which a drivesignal is not supplied from the vertical drive circuit 102.

In such a state, the charges 58 generated in the photoelectricconversion film 34 corresponding to the photoelectric conversion sectionPD1 of each of the pixels 10 a and 10 b are attracted to theaccumulation electrode 37 of the pixel 10 b. As a result, the charges 58generated in the photoelectric conversion film 34 are accumulated in thesemiconductor layer 35 near the accumulation electrode 37 in the pixel10 b. Note that the outflow destination of the charges 58 overflowingfrom the semiconductor layer 35 near the accumulation electrode 37 inthe pixel 10 b may be the floating diffusion region FD connected to thereadout electrode 36 of the pixel 10 b.

On the other hand, in the pixel 10 a, a charges 59 accumulated in thesemiconductor layer 35 near the accumulation electrode 37 in theprevious frame are held in the memory MEM. The charges 59 accumulated inthe memory MEM are sequentially read out by the readout operation forthe pixel 10 a executed in parallel during the exposure of the pixel 10b, and are used for generation of a pixel signal.

By executing the operation as described above, it is possible tosuppress a decrease in parasitic light receiving sensitivity due to thecharges overflowing from the accumulation region by the accumulationelectrode 37 in the semiconductor layer 35 flowing into the memory MEM.

1.9.10 10TH EXAMPLE

In the 10th example, a modification of the pixel 10 for realizing theglobal shutter drive exemplified in the ninth example will be described.FIG. 26 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 10th example ofthe present embodiment. In the above-described ninth example, during theexecution of the global shutter drive, the shield electrode 57positioned between the two pixels 10 a and 10 b forming a pair is turnedoff. On the other hand, in the 10th example, as depicted in FIG. 26 ,the shield electrode 57 between the two pixels 10 a and 10 b forming apair is omitted. As a result, since the configuration for driving theshield electrode 57 can be omitted, effects such as miniaturization byomitting the shield electrode 57 and the pixel drive line LD for drivingthe shield electrode 57 and reduction in power consumption at the timeof global shutter drive can be obtained.

1.9.11 11TH EXAMPLE

In the 11th example, another modification of the pixel 10 for realizingthe global shutter drive exemplified in the ninth example will bedescribed. FIG. 27 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 11th example ofthe present embodiment. As depicted in FIG. 27 , in the 11th example,the readout electrodes 36 and the floating diffusion regions FD of thetwo pixels 10 a and 10 b forming a pair are made common. As describedabove, even in a case where the readout electrode 36 and the floatingdiffusion region FD are shared by the two pixels 10 a and 10 b forming apair, global shutter drive can be realized by the driving described inthe ninth example.

1.9.12 12TH EXAMPLE

FIG. 28 is a vertical cross-sectional diagram depicting across-sectional structure example of the pixel according to the 12thexample of the present embodiment. As depicted in FIG. 28 , thesemiconductor layer 35 (including the first semiconductor layer 35A andthe second semiconductor layer 35B described in the eighth example) ineach of the examples described above and below may include two layers ofa first layer 35 a and a second layer 35 b. The second layer 35 b isprovided, for example, on a surface of the semiconductor layer 35 incontact with the insulating layer 53.

The second layer 35 b may be a film provided for the purpose of reducingthe interface trap level formed between the insulating layer 53 and thefirst layer 35 a. In addition, as a material constituting each of thefirst layer 35 a and the second layer 35 b, for example, the samematerial as the semiconductor layer 35 described above may be used.However, the first layer 35 a and the second layer 35 b may havedifferent properties depending on, for example, a difference incomposition and the like.

As described above, by providing the second layer 35 b for reducing theinterface trap level between the insulating layer 53 and the first layer35 a, the interface trap level formed between the insulating layer 53and the first layer 35 a is reduced, in a manner that the afterimagegenerated between the frames can be reduced.

1.9.13 13TH EXAMPLE

In the 13th example, some examples will be given of the position of thecolor filter 31 in each example described above or below. In each of theexamples described above or described below, the color filter 31 may bedisposed on the side of the light incident surface (the side of theon-chip lens 51) with respect to the photoelectric conversion film 34 asdepicted in FIG. 29 , or may be disposed on the side (the side of thecircuit chip 122 (not depicted)) opposite to the light incident surfacewith respect to the photoelectric conversion film 34 as depicted in FIG.30 . In a case where the color filter 31 is disposed on the sideopposite to the light incident surface with respect to the photoelectricconversion film 34, the color filter 31 may be disposed, for example, inthe insulating layer 53 as depicted in FIG. 30 .

1.9.14 14TH EXAMPLE

In each of the above-described examples, the configuration in which theshield electrode 57 (and the shield electrode 57B) is disposed betweenthe pixels 10 in order to prevent leakage (blooming) of charges betweenthe pixels 10 has been exemplified. On the other hand, in the 14thexample, a configuration will be described in which a fixed charge filmhaving the same polarity as the charge is disposed between the pixels 10instead of the shield electrode 57 (and the shield electrode 57B) toprevent leakage (blooming) of the charges between the pixels 10. Notethat, in the following, a case where the pixel 10 described in the firstexample is used as a base will be described, but the base pixel 10 isnot limited to the pixel 10 according to the first example, and may be apixel 10 according to another example.

FIG. 31 is a vertical cross-sectional diagram depicting across-sectional structure of the pixel according to the 14th example ofthe present embodiment. FIG. 32 is a horizontal cross-sectional diagramdepicting a D-D cross section in FIG. 31 . As depicted in FIGS. 31 and32 , in the pixel 10 according to the 14th example, a shield charge film67 is disposed between the adjacent pixels 10. The shield charge film 67may include a fixed charge film having the same polarity as the chargesgenerated in the photoelectric conversion film 34. In the 14th example,the shield charge film 67 is disposed on the same surface as the surfaceon which the accumulation electrode 37 is disposed. Note that the shieldcharge film 67 may be in contact with the side surface of theaccumulation electrode 37 or may be separated from the side surface ofthe accumulation electrode 37.

Also with such a structure, since the charges generated in thephotoelectric conversion film 34 of a certain pixel 10 and entering thesemiconductor layer 35 are suppressed from flowing out to the adjacentpixel 10, the quantum efficiency of the pixel 10 can be furtherimproved.

In addition, according to the present example, since the configurationfor driving the shield electrode 57 can be omitted, it is possible toreduce the size by omitting the shield electrode 57 and the pixel driveline LD for driving the shield electrode 57. Furthermore, in 14thexample, since it is not necessary to separate the accumulationelectrode 37 from the shield charge film 67, the accumulation electrode37 can be enlarged. As a result, charges can be efficiently collected bythe semiconductor layer 35 near the accumulation electrode 37, in amanner that further improvement in quantum efficiency can be expected.

In the following example, a modification of the position of the shieldcharge film 67 will be described.

1.9.15 15TH EXAMPLE

FIG. 33 is a vertical cross-sectional diagram depicting across-sectional structure of the pixel according to the 15th example ofthe present embodiment. As depicted in FIG. 33 , the shield charge film67 may be disposed between a surface of the insulating layer 53 on whichthe upper surface of the accumulation electrode 37 is disposed and thelower surface of the semiconductor layer 35 (other than thesemiconductor wiring 60), which is a boundary portion between theadjacent pixels 10. At that time, the region around the opening in theshield charge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction.

1.9.16 16TH EXAMPLE

FIG. 34 is a vertical cross-sectional diagram depicting across-sectional structure of the pixel according to the 16th example ofthe present embodiment. As depicted in FIG. 34 , the shield charge film67 may be disposed in the lower layer portion of the semiconductor layer35, that is, a region in contact with the insulating layer 53 in thesemiconductor layer 35, which is a boundary portion between the adjacentpixels 10. At that time, the region around the opening in the shieldcharge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction.

1.9.17 17TH EXAMPLE

FIG. 35 is a vertical cross-sectional diagram depicting across-sectional structure of the pixel according to the 17th example ofthe present embodiment. As depicted in FIG. 35 , the shield charge film67 may be disposed at a boundary portion between the adjacent pixels 10to replace the semiconductor layer 35 in this portion. At that time, theregion around the opening in the shield charge film 67 may overlap theouter peripheral portion of the accumulation electrode 37 in thevertical direction.

1.9.18 18TH EXAMPLE

FIG. 36 is a vertical cross-sectional diagram depicting across-sectional structure of the pixel according to the 18th example ofthe present embodiment. As depicted in FIG. 36 , the shield charge film67 may be disposed in the lower layer portion of the photoelectricconversion film 34, that is, a region in contact with the semiconductorlayer 35 in the photoelectric conversion film 34, which is a boundaryportion between the adjacent pixels 10 At that time, the region aroundthe opening in the shield charge film 67 may overlap the outerperipheral portion of the accumulation electrode 37 in the verticaldirection.

1.9.19 19TH EXAMPLE

FIG. 37 is a vertical cross-sectional diagram depicting across-sectional structure of the pixel according to the 19th example ofthe present embodiment. As depicted in FIG. 37 , the shield charge film67 may be disposed at a boundary portion between the adjacent pixels 10to replace the photoelectric conversion film 34 in this portion. At thattime, the region around the opening in the shield charge film 67 mayoverlap the outer peripheral portion of the accumulation electrode 37 inthe vertical direction.

1.9.20 20TH EXAMPLE

FIGS. 38 and 39 are vertical cross-sectional diagrams depicting across-sectional structure of the pixel according to the 20th example ofthe present embodiment. As depicted in FIGS. 38 and 39 , the shieldcharge film 67 may be disposed below the lower surface of theaccumulation electrode 37 in the insulating layer 53 (on the side of thereadout electrode 36), which is a boundary portion between the adjacentpixels 10. At that time, the region around the opening in the shieldcharge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction. In addition, theregion around the opening in the shield charge film 67 and the outerperipheral portion of the accumulation electrode 37 may be in contactwith each other as depicted in FIG. 38 , or may be separated from eachother in the vertical direction as depicted in FIG. 39 .

1.9.21 21ST EXAMPLE

FIG. 40 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 21st example ofthe present embodiment. As depicted in FIG. 40 , the transfer gate 11and the shield charge film 67 in the above-described example may bereplaced with an integrated fixed charge film 81.

1.9.22 22ND EXAMPLE

In the above-described example, the case where the semiconductor wiring60 is disposed at the center of each pixel 10 has been exemplified.However, for example, in a configuration in which the floating diffusionregion FD is shared by the plurality of pixels 10 as depicted in FIG. 10, the semiconductor wiring 60 can be shared among the pixels 10.Therefore, in the 22nd example to the 28th example described below, across-sectional structure in a case where the semiconductor wiring 60 isshared by the plurality of pixels 10 will be described as an example.Note that, in the 22nd example to the 28th example, a case where thereadout electrode 36 (floating diffusion region FD) and the accumulationelectrode 37 are disposed on the same surface (that is, thesemiconductor substrate 50 has the same height from the elementformation surface) is exemplified, but the present invention is notlimited to this, and they may be disposed on different surfaces as inthe above-described example.

FIG. 41 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 22nd example ofthe present embodiment. FIG. 42 is a horizontal cross-sectional diagramdepicting an E-E cross section in FIG. 41 . As depicted in FIGS. 41 and42 , in the 22nd example, the fixed charge film 81 in which the transfergate 11 and the shield charge film 67 are integrated is disposed betweenthe semiconductor layer 35 and the accumulation electrode 37 and thereadout electrode 36 (however, in a case where the readout electrode 36is disposed below the accumulation electrode 37, the side opposite tothe readout electrode 36 sandwiching the accumulation electrode 37). Inthe fixed charge film 81, an opening 81 a is provided in a regioncorresponding to the accumulation electrode 37 of each pixel 10. At thattime, the peripheral edge portion of the accumulation electrode 37 mayoverlap the fixed charge film 81 in the substrate thickness direction.The charges generated in the photoelectric conversion film 34 areaccumulated in an accumulation region corresponding to the opening 81 ain the semiconductor layer 35.

As described above, in the structure in which the accumulation electrode37 and the fixed charge film 81 are disposed in different layers, theaccumulation electrode 37 (and the opening 81 a) can be expanded in thedirection of the adjacent pixel 10. As a result, it is possible toexpand the accumulation region in the semiconductor layer 35, and thus,it is possible to store more charges.

Note that, in the present example, the case where the semiconductorlayer 35 is divided into the upper first layer 35 a and the lower secondlayer 35 b has been exemplified, but the present invention is notlimited to this, and the semiconductor layer 35 may be configured as asingle layer.

1.9.23 23RD EXAMPLE

FIG. 43 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 23rd example ofthe present embodiment. As depicted in FIG. 43 , the fixed charge film81 exemplified in the 22nd example may be disposed in a lower layerportion of the semiconductor layer 35. At that time, in a case where thesemiconductor layer 35 is divided into the upper first layer 35 a andthe lower second layer 35 b, the fixed charge film 81 may be disposed topartially replace the lower second layer 35 b.

1.9.24 24TH EXAMPLE

FIG. 44 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 24th example ofthe present embodiment. As depicted in FIG. 44 , in the 24th example,the fixed charge film 81 in the 23rd example is replaced with aninsulating film 82. Therefore, in the 24th example, a part of the lowerlayer of the semiconductor layer 35 protrudes toward the side of theaccumulation electrode 37 in the same shape as the opening 81 a depictedin FIG. 42 , for example.

In such a structure, by controlling the drive signal applied to theaccumulation electrode 37, it is possible to control accumulation anddischarge of charges to the portion of the semiconductor layer 35protruding to the side of the accumulation electrode 37. Therefore,similarly to other examples, it is possible to suppress leakage of thestored charges to the side of the readout electrode 36 and leakage(blooming) to the adjacent pixel 10.

1.9.25 25TH EXAMPLE

FIG. 45 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 25th example ofthe present embodiment. FIG. 46 is a horizontal cross-sectional diagramdepicting an F-F cross section in FIG. 45 . As depicted in FIGS. 45 and46 , in the 25th example, for example, in the same structure as the 24thexample, the fixed charge film 81 is replaced with a fixed charge film83 in which a portion corresponding to the transfer gate 11 is omitted.That is, the fixed charge film 83 according to the present examplecorresponds to the shield charge film 67 in the above-described example.

As described above, even in a case where the transfer gate 11 isomitted, it is possible to suppress charges leakage (blooming) betweenthe pixels 10, and thus, it is possible to improve the quantumefficiency.

1.9.26 26TH EXAMPLE

FIG. 47 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 26th example ofthe present embodiment. FIG. 48 is a horizontal cross-sectional diagramdepicting a G-G cross section in FIG. 47 . As depicted in FIGS. 47 and48 , in the 26th example, for example, in the same structure as the 24thexample, the fixed charge film 81 is replaced with a fixed charge film84 in which a portion corresponding to the shield charge film 67 isomitted. That is, the fixed charge film 83 according to the presentexample corresponds to the transfer gate 11 in the above-describedexample.

As described above, even in a case where the shield charge film 67 isomitted, it is possible to suppress leakage of the accumulated chargesto the floating diffusion region FD, and thus, it is possible to improvethe quantum efficiency.

1.9.27 27TH EXAMPLE

FIG. 49 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 27th example ofthe present embodiment. As depicted in FIG. 49 , in 27th example, astructure in which the semiconductor layer 35 is not divided into thefirst layer 35 a and the second layer 35 b in the same structure as inthe 23rd example described above with reference to FIG. 43 is depicted.As described above, in a case where the semiconductor layer 35 is notdivided into the first layer 35 a and the second layer 35 b, the fixedcharge film 81 may be disposed in a lower layer portion of thesemiconductor layer 35.

1.9.28 28TH EXAMPLE

FIG. 50 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 28th example ofthe present embodiment. As depicted in FIG. 50 , in the 28th example, apotential control electrode 85 for controlling a potential is disposedin the insulating layer 53 on the opposite side (also referred to as alower layer) to the semiconductor layer 35 sandwiching the accumulationelectrode 37 (and the readout electrode 36).

As described above, by disposing the potential control electrode 85 forcontrolling the potential on the below the accumulation electrode 37(and the readout electrode 36), it is possible to assist the flow ofcharges from the accumulation region of the semiconductor layer 35 tothe floating diffusion region FD, and thus, it is possible to read outcharges more smoothly.

1.9.29 29TH EXAMPLE

In the 29th example to the 34th example, arrangement variations of theshield charge film 67 will be described. Note that, in the 29th exampleto the 34th example, similarly to the 22nd example to the 28th example,a case where the readout electrode 36 (floating diffusion region FD) andthe accumulation electrode 37 are disposed on the same surface isexemplified, but the present invention is not limited to this, and theymay be disposed on different surfaces as in the above-described example.

FIG. 51 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 29th example ofthe present embodiment. As depicted in FIG. 51 , the shield charge film67 may be disposed on the same surface as the accumulation electrode 37,which is a boundary portion between the adjacent pixels 10 At that time,the shield charge film 67 and the accumulation electrode 37 may be incontact with each other or may be separated from each other.

1.9.30 30TH EXAMPLE

FIG. 52 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 30th example ofthe present embodiment. As depicted in FIG. 52 , the shield charge film67 may be disposed between a surface of the insulating layer 53 on whichthe upper surface of the accumulation electrode 37 is disposed and thelower surface of the semiconductor layer 35 (other than thesemiconductor wiring 60), which is a boundary portion between theadjacent pixels 10. At that time, the region around the opening in theshield charge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction.

1.9.31 31ST EXAMPLE

FIG. 53 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 31st example ofthe present embodiment. As depicted in FIG. 53 , the shield charge film67 may be disposed below the lower surface of the accumulation electrode37 in the insulating layer 53, which is a boundary portion between theadjacent pixels 10 At that time, the region around the opening in theshield charge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction. In addition, theregion around the opening in the shield charge film 67 and the outerperipheral portion of the accumulation electrode 37 may be in contactwith each other or may be separated from each other in the verticaldirection.

1.9.32 32ND EXAMPLE

FIG. 54 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 32nd example ofthe present embodiment. As depicted in FIG. 54 , the shield charge film67 may be disposed in the lower layer portion of the semiconductor layer35, that is, a region in contact with the insulating layer 53 in thesemiconductor layer 35, which is a boundary portion between the adjacentpixels 10 At that time, in a case where the semiconductor layer 35 isdivided into the first layer 35 a and the second layer 35 b, the shieldcharge film 67 may be disposed in the lower layer portion of the firstlayer 35 a. In addition, the region around the opening in the shieldcharge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction.

1.9.33 33RD EXAMPLE

FIG. 55 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 33rd example ofthe present embodiment. As depicted in FIG. 55 , the shield charge film67 may be disposed in the lower layer portion of the photoelectricconversion film 34, that is, a region in contact with the semiconductorlayer 35 in the photoelectric conversion film 34, which is a boundaryportion between the adjacent pixels 10 At that time, the region aroundthe opening in the shield charge film 67 may overlap the outerperipheral portion of the accumulation electrode 37 in the verticaldirection.

1.9.34 34TH EXAMPLE

FIG. 56 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 34th example ofthe present embodiment. As depicted in FIG. 56 , the shield charge film67 may be disposed at a boundary portion between the adjacent pixels 10to replace the photoelectric conversion film 34 in this portion. At thattime, the region around the opening in the shield charge film 67 mayoverlap the outer peripheral portion of the accumulation electrode 37 inthe vertical direction.

1.9.35 35TH EXAMPLE

In the 35th example to the 40th example, arrangement variations of thetransfer gate 11 will be described. Note that, in the 35th example tothe 40th example, similarly to the 22nd example to the 34th example, acase where the readout electrode 36 (floating diffusion region FD) andthe accumulation electrode 37 are disposed on the same surface isexemplified, but the present invention is not limited to this, and theymay be disposed on different surfaces as in the above-described example.

FIG. 57 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 35th example ofthe present embodiment. As depicted in FIG. 57 , the transfer gate 11may be disposed between the readout electrode 36 and the accumulationelectrode 37, and between the surface of the insulating layer 53 onwhich the upper surface of the accumulation electrode 37 is disposed andthe lower surface of the semiconductor layer 35 (other than thesemiconductor wiring 60). At this time, the peripheral edge of thetransfer gate 11 may overlap the readout electrode 36 and theaccumulation electrode 37 in the vertical direction.

1.9.36 36TH EXAMPLE

FIG. 58 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 36th example ofthe present embodiment. As depicted in FIG. 58 , the transfer gate 11may be disposed between the readout electrode 36 and the accumulationelectrode 37 on the same surface as the readout electrode 36 and theaccumulation electrode 37. At that time, the transfer gate 11, thereadout electrode 36, and the accumulation electrode 37 may be incontact with each other or may be separated from each other.

1.9.37 37TH EXAMPLE

FIG. 59 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 37th example ofthe present embodiment. As depicted in FIG. 59 , the transfer gate 11may be disposed between the readout electrode 36 and the accumulationelectrode 37 and below the lower surface of the accumulation electrode37 in the insulating layer 53. At this time, the peripheral edge of thetransfer gate 11 may overlap a part of the readout electrode 36 and theaccumulation electrode 37 in the vertical direction. In addition, theperipheral edge of the transfer gate 11, the readout electrode 36, andthe accumulation electrode 37 may be in contact with each other or maybe separated from each other in the vertical direction.

1.9.38 38TH EXAMPLE

FIG. 60 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 38th example ofthe present embodiment. As depicted in FIG. 60 , the transfer gate 11may be disposed between the readout electrode 36 and the accumulationelectrode 37 in a lower layer portion of the semiconductor layer 35,that is, in a region of the semiconductor layer 35 in contact with theinsulating layer 53. At that time, in a case where the semiconductorlayer 35 is divided into the first layer 35 a and the second layer 35 b,the transfer gate 11 may be disposed on the lower layer of the firstlayer 35 a. In addition, the peripheral edge of the transfer gate 11 mayoverlap the readout electrode 36 and the accumulation electrode 37 inthe vertical direction.

1.9.39 39TH EXAMPLE

FIG. 61 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 39th example ofthe present embodiment. As depicted in FIG. 61 , the transfer gate 11may be disposed between the readout electrode 36 and the accumulationelectrode 37 in a lower layer portion of the photoelectric conversionfilm 34, that is, in a region of the photoelectric conversion film 34 incontact with the semiconductor layer 35. At this time, the peripheraledge of the transfer gate 11 may overlap the readout electrode 36 andthe accumulation electrode 37 in the vertical direction.

1.9.40 40TH EXAMPLE

FIG. 62 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 40th example ofthe present embodiment. As depicted in FIG. 62 , the transfer gate 11may be disposed between the readout electrode 36 and the accumulationelectrode 37 to replace the photoelectric conversion film 34 in thisportion. At this time, the peripheral edge of the transfer gate 11 mayoverlap the readout electrode 36 and the accumulation electrode 37 inthe vertical direction.

1.9.41 41ST EXAMPLE

In the 22nd example to the 40th example described above, the arrangementvariation of the shield charge film 67 and the transfer gate 11 in acase where the readout electrode 36 (floating diffusion region FD) andthe accumulation electrode 37 are disposed on the same surface has beendescribed. On the other hand, in the 41st example to the 51st exampledescribed below, similarly to the first example to the 21st exampledescribed above, arrangement variations in a case where the readoutelectrode 36 (floating diffusion region FD) is disposed below theaccumulation electrode 37 will be described.

FIG. 63 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 41st example ofthe present embodiment. As depicted in FIG. 63 , in the 41st example,the transfer gate 11 and the shield charge film 67 may be disposed onthe same surface as the readout electrode 36 and the accumulationelectrode 37. At this time, the transfer gate 11, the readout electrode36, and the accumulation electrode 37 may be in contact with each otheror may be separated from each other, and the shield charge film 67 andthe accumulation electrode 37 may be in contact with each other or maybe separated from each other.

1.9.42 42ND EXAMPLE

FIG. 64 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 42nd example ofthe present embodiment. As depicted in FIG. 64 , in the 42nd example,the transfer gate 11 may be disposed between the readout electrode 36and the accumulation electrode 37 and below the lower surface of theaccumulation electrode 37 in the insulating layer 53. At this time, theperipheral edge of the transfer gate 11 may overlap a part of thereadout electrode 36 and the accumulation electrode 37 in the verticaldirection. In addition, the peripheral edge of the transfer gate 11, thereadout electrode 36, and the accumulation electrode 37 may be incontact with each other or may be separated from each other in thevertical direction.

The shield charge film 67 may be disposed in the lower layer portion ofthe semiconductor layer 35, that is, a region in contact with theinsulating layer 35 in the photoelectric conversion film 34, which is aboundary portion between the adjacent pixels 10. At that time, in a casewhere the semiconductor layer 35 is divided into the first layer 35 aand the second layer 35 b, the shield charge film 67 may be disposed toreplace a part of the second layer 35 b. In addition, the region aroundthe opening in the shield charge film 67 may overlap the outerperipheral portion of the accumulation electrode 37 in the verticaldirection.

1.9.43 43RD EXAMPLE

FIG. 65 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 43rd example ofthe present embodiment. As depicted in FIG. 65 , in the 43rd example,the transfer gate 11 is replaced with a transfer gate including a gateelectrode 91 in a structure similar to the cross-sectional structureaccording to the 42nd example described above with reference to FIG. 64. The gate electrode 91 may be made of, for example, a transparentconductive material similar to the accumulation electrode 37 and thelike, and a potential barrier is formed in the semiconductor wiring 60according to a drive signal applied from the vertical drive circuit 102to turn on/off conduction of the semiconductor wiring 60.

1.9.44 44TH EXAMPLE

FIG. 66 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 44th example ofthe present embodiment. As depicted in FIG. 66 , in the 44th example, inthe same structure as the cross-sectional structure according to 41stexample described above with reference to FIG. 63 , the transfer gate 11is disposed between the readout electrode 36 and the accumulationelectrode 37 and below the lower surface of the accumulation electrode37 in the insulating layer 53, and the shield charge film 67 is replacedwith the shield electrode 57, similarly to the 42nd example.

1.9.45 45TH EXAMPLE

FIG. 67 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 45th example ofthe present embodiment. As depicted in FIG. 67 , in the 45th example, inthe same structure as the cross-sectional structure according to the43th example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed at the boundary portion between the adjacentpixels 10 and below the lower surface of the accumulation electrode 37in the insulating layer 53 (on the side of the readout electrode 36). Atthat time, the region around the opening in the shield charge film 67may overlap the outer peripheral portion of the accumulation electrode37 in the vertical direction. In addition, the region around the openingin the shield charge film 67 and the outer peripheral portion of theaccumulation electrode 37 may be in contact with each other or may beseparated from each other in the vertical direction.

1.9.46 46TH EXAMPLE

FIG. 68 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 46th example ofthe present embodiment. As depicted in FIG. 68 , in the 46th example, inthe same structure as the cross-sectional structure according to the43th example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed at the boundary portion between the adjacentpixels 10 and on the same surface as the accumulation electrode 37. Atthat time, the shield charge film 67 and the accumulation electrode 37may be in contact with each other or may be separated from each other.

1.9.47 47TH EXAMPLE

FIG. 69 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 47th example ofthe present embodiment. As depicted in FIG. 69 , in the 47th example, inthe same structure as the cross-sectional structure according to the43rd example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed between a surface of the insulating layer 53on which the upper surface of the accumulation electrode 37 is disposedand the lower surface of the semiconductor layer 35 (other than thesemiconductor wiring 60), which is a boundary portion between theadjacent pixels 10. At that time, the region around the opening in theshield charge film 67 may overlap the outer peripheral portion of theaccumulation electrode 37 in the vertical direction.

1.9.48 48TH EXAMPLE

FIG. 70 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 48th example ofthe present embodiment. As depicted in FIG. 70 , in the 48th example, inthe same structure as the cross-sectional structure according to the43th example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed in the lower layer portion of thesemiconductor layer 35, that is a region in contact with the insulatinglayer 53 in the semiconductor layer 35, which is a boundary portionbetween the adjacent pixels 10. At that time, in a case where thesemiconductor layer 35 is divided into the first layer 35 a and thesecond layer 35 b, the shield charge film 67 may be disposed in thelower layer portion of the first layer 35 a. In addition, the regionaround the opening in the shield charge film 67 may overlap the outerperipheral portion of the accumulation electrode 37 in the verticaldirection.

1.9.49 49TH EXAMPLE

FIG. 71 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 49th example ofthe present embodiment. As depicted in FIG. 71 , in the 49th example, inthe same structure as the cross-sectional structure according to the43th example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed to replace the semiconductor layer 35positioned at the boundary portion between the adjacent pixels 10. Atthat time, in a case where the semiconductor layer 35 is divided intothe first layer 35 a and the second layer 35 b, the shield charge film67 may be disposed to replace a part of the first layer 35 a. Inaddition, the region around the opening in the shield charge film 67 mayoverlap the outer peripheral portion of the accumulation electrode 37 inthe vertical direction.

1.9.50 50TH EXAMPLE

FIG. 72 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 50th example ofthe present embodiment. As depicted in FIG. 72 , in the 50th example, inthe same structure as the cross-sectional structure according to the43th example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed in the lower layer portion of thephotoelectric conversion film 34, that is a region in contact with thesemiconductor layer 35 in the photoelectric conversion film 34, which isa boundary portion between the adjacent pixels 10. At that time, theregion around the opening in the shield charge film 67 may overlap theouter peripheral portion of the accumulation electrode 37 in thevertical direction.

1.9.51 51ST EXAMPLE

FIG. 73 is a vertical cross-sectional diagram depicting across-sectional structure of a pixel according to the 51st example ofthe present embodiment. As depicted in FIG. 73 , in the 51st example, inthe same structure as the cross-sectional structure according to the43th example described above with reference to FIG. 65 , the shieldcharge film 67 is disposed to replace the photoelectric conversion film34 in this portion at the boundary portion between the adjacent pixels10. At that time, the region around the opening in the shield chargefilm 67 may overlap the outer peripheral portion of the accumulationelectrode 37 in the vertical direction.

1.10 SUMMARY

As described above, according to the present embodiment, the potentialbarrier between the accumulation electrode 37 and the readout electrode36 is controlled using the transfer gate 11. As a result, it is possibleto suppress leakage of the charges accumulated in the semiconductorlayer 35 near the accumulation electrode 37 to the side of the readoutelectrode 36, and thus, it is possible to improve the quantumefficiency. In addition, the potential barrier between the adjacentpixels 10 is controlled using the shield electrode 57 or the shieldcharge film 67. As a result, since the charges generated in thephotoelectric conversion film 34 of a certain pixel 10 and entering thesemiconductor layer 35 are suppressed from flowing out to the adjacentpixel 10 (blooming), the quantum efficiency of the pixel 10 can befurther improved.

2. VARIATION OF CROSS-SECTIONAL STRUCTURE

Here, some variations of the cross-sectional structure of the imagesensor 100 according to the above-described embodiment will bedescribed. Note that a structure that is not particularly limited in thefollowing description may be the same as the cross-sectional structuredescribed above.

2.1 FIRST VARIATION

FIG. 74 is a vertical cross-sectional diagram depicting across-sectional structure example of the image sensor according to thefirst variation. FIG. 75 is a horizontal cross-sectional diagramdepicting the I-I cross section in FIG. 74 . As depicted in FIGS. 74 and75 , the image sensor 100 is, for example, a stacked-type imagingelement in which RGB pixels 10 disposed on the upstream side withrespect to incident light and IR pixels 20 disposed on the downstreamside are stacked. On the upstream side, for example, four RGB pixels 10of one RGB pixel 10 including the color filter 31 r that selectivelytransmits red light (R), two RGB pixels 10 including the color filter 31g that selectively transmits green light (G), and one RGB pixel 10including the color filter 31 b that selectively transmits blue light(B) are disposed to form a unit array of 2 rows×2 columns in the Bayerarray. In the pixel array section 101, this unit array is a repeatingunit, and is repeatedly disposed in an array including a row directionand a column direction.

In a unit array including four RGB pixels 10 disposed in 2 rows×2columns, two color filters 31 g that selectively transmit green light(G) are disposed on a diagonal line, and color filters 31 r and 31 bthat selectively transmit red light (R) and blue light (B) are disposedone by one on an orthogonal diagonal line. The photoelectric conversionfilm 34 of each of the RGB pixels 10 provided with one of the colorfilters 31 r, 31 g, and 31 b photoelectrically converts color lightcorresponding to each of the color filters 31 to generate charges.

Of the light transmitted through the color filters 31, light in thevisible light region (red light (R), green light (G) and blue light (B))is absorbed by the photoelectric conversion film 34 of the RGB pixel 10provided with each color filter 31, and other light, for example, lightin the infrared light region (for example, 700 nm or more and 1000 nm orless) (IR light) is transmitted through the photoelectric conversionfilm 34. The IR light transmitted through the photoelectric conversionfilm 34 is detected by the photoelectric conversion section PD1 of theIR pixel 20 disposed downstream with respect to each RGB pixel 10. Asdescribed above, the image sensor 100 according to the first variationcan simultaneously generate both the visible light image and theinfrared light image.

2.2 SECOND VARIATION

FIG. 76 is a vertical cross-sectional diagram depicting across-sectional structure example of the image sensor according to thesecond variation. FIG. 77 is a horizontal cross-sectional diagramdepicting the II-II cross section in FIG. 76 . In the first variationdescribed above, an example has been described in which the color filter31 that selectively transmits the red light (R), the green light (G),and the blue light (B) is provided above the photoelectric conversionfilm 34 (light incident side), but the color filter 31 may be providedbetween the photoelectric conversion section PD1 and the photoelectricconversion section PD2, for example, as depicted in FIG. 76 .

In the second variation, for example, the color filter 31 has aconfiguration in which the color filter 31r that selectively transmitsat least red light (R) and the color filter 31 b that selectivelytransmits at least blue light (B) are disposed diagonally to each other.The photoelectric conversion film 34 positioned on the upstream sidewith respect to the incident light is configured to selectively absorb awavelength corresponding to green light, for example. As a result,signals corresponding to the three primary colors of RGB can be acquiredin the photoelectric conversion section PD1 on the upstream side and thephotoelectric conversion section PD2 on the downstream side disposedbelow the color filters 31 r and 31 b, respectively. In the secondvariation, since the light receiving areas of the photoelectricconversion sections PD1 and PD2 of the three primary colors of RGB canbe enlarged as compared with an imaging element having a general Bayerarray, the S/N ratio can be improved.

3. CONFIGURATION EXAMPLE OF IMAGING DEVICE

FIG. 78 is a block diagram depicting a configuration example of anembodiment of an imaging device as an electronic apparatus to which thepresent disclosure is applied.

An imaging device 2000 in FIG. 78 is a video camera, a digital stillcamera, and the like. The imaging device 2000 includes a lens group2001, a solid-state imaging device 2002, a DSP circuit 2003, a framememory 2004, a display section 2005, a recording unit 2006, an operationunit 2007, and a power supply unit 2008. The DSP circuit 2003, the framememory 2004, the display section 2005, the recording unit 2006, theoperation unit 2007, and the power supply unit 2008 are mutuallyconnected via a bus line 2009.

The lens group 2001 captures incident light (image light) from a subjectand forms an image on the imaging surface of the solid-state imagingdevice 2002. The solid-state imaging device 2002 may be the image sensor100 according to the above-described embodiment. The solid-state imagingdevice 2002 converts the light amount of the incident light imaged onthe imaging surface by the lens group 2001 into an electric signal inunits of pixels and supplies the electric signal to the DSP circuit 2003as a pixel signal.

The DSP circuit 2003 performs predetermined image processing on thepixel signal supplied from the solid-state imaging device 2002, suppliesthe image signal after the image processing to the frame memory 2004 inunits of frames, and temporarily stores the image signal.

The display section 2005 includes, for example, a panel type displaydevice such as a liquid crystal panel or an organic electro luminescence(EL) panel, and displays an image on the basis of the pixel signal inframe units temporarily stored in the frame memory 2004.

The recording unit 2006 includes a digital versatile disk (DVD), a flashmemory, and the like, and reads and records the pixel signals in unitsof frames temporarily stored in the frame memory 2004.

The operation unit 2007 issues operation commands for various functionsof the imaging device 2000 under operation by the user. The power supplyunit 2008 appropriately supplies power to the DSP circuit 2003, theframe memory 2004, the display section 2005, the recording unit 2006,and the operation unit 2007.

The electronic apparatus to which the present technology is applied maybe an apparatus using an image sensor as an image capturing unit(photoelectric conversion section), and examples include a mobileterminal apparatus having an imaging function, a copying machine usingan image sensor as an image reading unit, and the like, in addition tothe imaging device 2000.

4. APPLICATION EXAMPLE TO MOBILE BODY

The technology according to the present disclosure (the presenttechnology) can be applied to various products. For example, thetechnology according to the present disclosure may be realized bydevices mounted on any type of mobile body such as an automobile, anelectric car, a hybrid electric car, a motorcycle, a bicycle, a personalmobility, an airplane, a drone, a ship, and a robot.

FIG. 79 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

A vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 79 , the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automated driving, which makes the vehicle to travelautomatedly without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 79 , anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 80 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 80 , the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of a vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimaging section 12105 provided to the upper portion of the windshieldwithin the interior of the vehicle is used mainly to detect a precedingvehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, orthe like.

Incidentally, FIG. 80 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automated drivingthat makes the vehicle travel automatedly without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

An example of the vehicle control system to which the technologyaccording to the present disclosure can be applied has been describedabove. The technology according to the present disclosure may be appliedto, for example, the imaging section 12031 and the like among theabove-described configurations. The imaging sections 12101, 12102,12103, 12104, 12105, and the like depicted in FIG. 80 may be mounted onthe vehicle 12100. By applying the technology according to the presentdisclosure to the imaging sections 12101, 12102, 12103, 12104, 12105,and the like, the sensitivity of the imaging section 12031 can beimproved. Therefore, not only a clearer image can be displayed on thedriver and the like, but also the accuracy of various types ofprocessing using the image acquired by the imaging section 12031 can beimproved.

5. APPLICATION EXAMPLE TO ENDOSCOPIC SURGERY SYSTEM

The technology according to the present disclosure (the presenttechnology) can be applied to various products. For example, thetechnology according to the present disclosure may be applied to anendoscopic surgery system.

FIG. 81 is a view depicting an example of a schematic configuration ofan endoscopic surgery system to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

In FIG. 81 , a state is illustrated in which a surgeon (medical doctor)11131 is using an endoscopic surgery system 11000 to perform surgery fora patient 11132 on a patient bed 11133. As depicted, the endoscopicsurgery system 11000 includes an endoscope 11100, other surgical tools11110 such as a pneumoperitoneum tube 11111 and an energy treatment tool11112, a supporting arm apparatus 11120 which supports the endoscope11100 thereon, and a cart 11200 on which various apparatus forendoscopic surgery are mounted.

The endoscope 11100 includes a lens barrel 11101 having a region of apredetermined length from a distal end thereof to be inserted into abody lumen of the patient 11132, and a camera head 11102 connected to aproximal end of the lens barrel 11101. In the example depicted, theendoscope 11100 is depicted which includes as a hard mirror having thelens barrel 11101 of the hard type. However, the endoscope 11100 mayotherwise be included as a soft mirror having the lens barrel 11101 ofthe soft type.

The lens barrel 11101 has, at a distal end thereof, an opening in whichan objective lens is fitted. A light source apparatus 11203 is connectedto the endoscope 11100 such that light generated by the light sourceapparatus 11203 is introduced to a distal end of the lens barrel 11101by a light guide extending in the inside of the lens barrel 11101 and isirradiated toward an observation target in a body lumen of the patient11132 through the objective lens. It is to be noted that the endoscope11100 may be a direct view mirror or may be a perspective view mirror ora side view mirror.

An optical system and an image pickup element are provided in the insideof the camera head 11102 such that reflected light (observation light)from the observation target is condensed on the image pickup element bythe optical system. The observation light is photo-electricallyconverted by the image pickup element to generate an electric signalcorresponding to the observation light, namely, an image signalcorresponding to an observation image. The image signal is transmittedas RAW data to a CCU 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU) or the like and integrally controls operation ofthe endoscope 11100 and a display apparatus 11202. Further, the CCU11201 receives an image signal from the camera head 11102 and performs,for the image signal, various image processes for displaying an imagebased on the image signal such as, for example, a development process(demosaic process).

The display apparatus 11202 displays thereon an image based on an imagesignal, for which the image processes have been performed by the CCU11201, under the control of the CCU 11201.

The light source apparatus 11203 includes a light source such as, forexample, a light emitting diode (LED) and supplies irradiation lightupon imaging of a surgical region to the endoscope 11100.

An inputting apparatus 11204 is an input interface for the endoscopicsurgery system 11000. A user can perform inputting of various kinds ofinformation or instruction inputting to the endoscopic surgery system11000 through the inputting apparatus 11204. For example, the user wouldinput an instruction or a like to change an image pickup condition (typeof irradiation light, magnification, focal distance or the like) by theendoscope 11100.

A treatment tool controlling apparatus 11205 controls driving of theenergy treatment tool 11112 for cautery or incision of a tissue, sealingof a blood vessel or the like. A pneumoperitoneum apparatus 11206 feedsgas into a body lumen of the patient 11132 through the pneumoperitoneumtube 11111 to inflate the body lumen in order to secure the field ofview of the endoscope 11100 and secure the working space for thesurgeon. A recorder 11207 is an apparatus capable of recording variouskinds of information relating to surgery. A printer 11208 is anapparatus capable of printing various kinds of information relating tosurgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus 11203 which suppliesirradiation light when a surgical region is to be imaged to theendoscope 11100 may include a white light source which includes, forexample, an LED, a laser light source or a combination of them. Where awhite light source includes a combination of red, green, and blue (RGB)laser light sources, since the output intensity and the output timingcan be controlled with a high degree of accuracy for each color (eachwavelength), adjustment of the white balance of a picked up image can beperformed by the light source apparatus 11203. Further, in this case, iflaser beams from the respective RGB laser light sources are irradiatedtime-divisionally on an observation target and driving of the imagepickup elements of the camera head 11102 are controlled in synchronismwith the irradiation timings. Then images individually corresponding tothe R, G and B colors can be also picked up time-divisionally. Accordingto this method, a color image can be obtained even if color filters arenot provided for the image pickup element.

Further, the light source apparatus 11203 may be controlled such thatthe intensity of light to be outputted is changed for each predeterminedtime. By controlling driving of the image pickup element of the camerahead 11102 in synchronism with the timing of the change of the intensityof light to acquire images time-divisionally and synthesizing theimages, an image of a high dynamic range free from underexposed blockedup shadows and overexposed highlights can be created.

Further, the light source apparatus 11203 may be configured to supplylight of a predetermined wavelength band ready for special lightobservation. In special light observation, for example, by utilizing thewavelength dependency of absorption of light in a body tissue toirradiate light of a narrow band in comparison with irradiation lightupon ordinary observation (namely, white light), narrow band observation(narrow band imaging) of imaging a predetermined tissue such as a bloodvessel of a superficial portion of the mucous membrane or the like in ahigh contrast is performed. Alternatively, in special light observation,fluorescent observation for obtaining an image from fluorescent lightgenerated by irradiation of excitation light may be performed. Influorescent observation, it is possible to perform observation offluorescent light from a body tissue by irradiating excitation light onthe body tissue (autofluorescence observation) or to obtain afluorescent light image by locally injecting a reagent such asindocyanine green (ICG) into a body tissue and irradiating excitationlight corresponding to a fluorescent light wavelength of the reagentupon the body tissue. The light source apparatus 11203 can be configuredto supply such narrow-band light and/or excitation light suitable forspecial light observation as described above.

FIG. 82 is a block diagram depicting an example of a functionalconfiguration of the camera head 11102 and the CCU 11201 depicted inFIG. 81 .

The camera head 11102 includes a lens unit 11401, an image pickup unit11402, a driving unit 11403, a communication unit 11404 and a camerahead controlling unit 11405. The CCU 11201 includes a communication unit11411, an image processing unit 11412 and a control unit 11413. Thecamera head 11102 and the CCU 11201 are connected for communication toeach other by a transmission cable 11400.

The lens unit 11401 is an optical system, provided at a connectinglocation to the lens barrel 11101. Observation light taken in from adistal end of the lens barrel 11101 is guided to the camera head 11102and introduced into the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and afocusing lens.

The number of image pickup elements which is included by the imagepickup unit 11402 may be one (single-plate type) or a plural number(multi-plate type). Where the image pickup unit 11402 is configured asthat of the multi-plate type, for example, image signals correspondingto respective R, G and B are generated by the image pickup elements, andthe image signals may be synthesized to obtain a color image. The imagepickup unit 11402 may also be configured so as to have a pair of imagepickup elements for acquiring respective image signals for the right eyeand the left eye ready for three dimensional (3D) display. If 3D displayis performed, then the depth of a living body tissue in a surgicalregion can be comprehended more accurately by the surgeon 11131. It isto be noted that, where the image pickup unit 11402 is configured asthat of stereoscopic type, a plurality of systems of lens units 11401are provided corresponding to the individual image pickup elements.

Further, the image pickup unit 11402 may not necessarily be provided onthe camera head 11102. For example, the image pickup unit 11402 may beprovided immediately behind the objective lens in the inside of the lensbarrel 11101.

The driving unit 11403 includes an actuator and moves the zoom lens andthe focusing lens of the lens unit 11401 by a predetermined distancealong an optical axis under the control of the camera head controllingunit 11405. Consequently, the magnification and the focal point of apicked up image by the image pickup unit 11402 can be adjusted suitably.

The communication unit 11404 includes a communication apparatus fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalacquired from the image pickup unit 11402 as RAW data to the CCU 11201through the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head controlling unit 11405.The control signal includes information relating to image pickupconditions such as, for example, information that a frame rate of apicked up image is designated, information that an exposure value uponimage picking up is designated and/or information that a magnificationand a focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the framerate, exposure value, magnification or focal point may be designated bythe user or may be set automatically by the control unit 11413 of theCCU 11201 on the basis of an acquired image signal. In the latter case,an auto exposure (AE) function, an auto focus (AF) function and an autowhite balance (AWB) function are incorporated in the endoscope 11100.

The camera head controlling unit 11405 controls driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedthrough the communication unit 11404.

The communication unit 11411 includes a communication apparatus fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted thereto from the camera head 11102 through the transmissioncable 11400.

Further, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electricalcommunication, optical communication or the like.

The image processing unit 11412 performs various image processes for animage signal in the form of RAW data transmitted thereto from the camerahead 11102.

The control unit 11413 performs various kinds of control relating toimage picking up of a surgical region or the like by the endoscope 11100and display of a picked up image obtained by image picking up of thesurgical region or the like. For example, the control unit 11413 createsa control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 controls, on the basis of an imagesignal for which image processes have been performed by the imageprocessing unit 11412, the display apparatus 11202 to display a pickedup image in which the surgical region or the like is imaged. Thereupon,the control unit 11413 may recognize various objects in the picked upimage using various image recognition technologies. For example, thecontrol unit 11413 can recognize a surgical tool such as forceps, aparticular living body region, bleeding, mist when the energy treatmenttool 11112 is used and so forth by detecting the shape, color and soforth of edges of objects included in a picked up image. The controlunit 11413 may cause, when it controls the display apparatus 11202 todisplay a picked up image, various kinds of surgery supportinginformation to be displayed in an overlapping manner with an image ofthe surgical region using a result of the recognition. Where surgerysupporting information is displayed in an overlapping manner andpresented to the surgeon 11131, the burden on the surgeon 11131 can bereduced and the surgeon 11131 can proceed with the surgery withcertainty.

The transmission cable 11400 which connects the camera head 11102 andthe CCU 11201 to each other is an electric signal cable ready forcommunication of an electric signal, an optical fiber ready for opticalcommunication or a composite cable ready for both of electrical andoptical communications.

Here, while, in the example depicted, communication is performed bywired communication using the transmission cable 11400, thecommunication between the camera head 11102 and the CCU 11201 may beperformed by wireless communication.

An example of the endoscopic surgery system to which the technologyaccording to the present disclosure may be applied has been describedabove. The technology according to the present disclosure may be appliedto, for example, the endoscope 11100 and (the image pickup unit 11402)of the camera head 11102, (the image processing unit 11412) of theCCU11201, and the like among the above-described configurations. Byapplying the technology according to the present disclosure to theseconfigurations, it is possible to obtain an effect that a clearer imagecan be displayed to the operator.

Note that, here, the endoscopic surgery system has been described as anexample, but the technology according to the present disclosure may beapplied to, for example, a microscopic surgery system and the like.

Although the embodiments of the present disclosure have been describedabove, the technical scope of the present disclosure is not limited tothe above-described embodiments as it is, and various modifications canbe made without departing from the gist of the present disclosure. Inaddition, components of different embodiments and modifications may beappropriately combined.

In addition, the effects of the embodiments described in the presentspecification are merely examples and are not limited, and other effectsmay be provided.

Note that the present technology can also have the configuration below.

-   (1)

A solid-state imaging device including:

a plurality of pixels arranged in a matrix, wherein

each of the pixels includes

a first semiconductor layer,

a photoelectric conversion section disposed on the first semiconductorlayer on a side of a first surface,

an accumulation electrode disposed on the first semiconductor layerclose to a side of a second surface on a side opposite to the firstsurface,

a wiring extending from the second surface of the first semiconductorlayer,

a floating diffusion region connected to the first semiconductor layervia the wiring, and

a first gate that forms a potential barrier in a charge flow path fromthe first semiconductor layer to the floating diffusion region via thewiring.

-   (2)

The solid-state imaging device according to (1), wherein

the first gate is a fixed charge film having a same polarity as apolarity of a charge generated by photoelectric conversion by thephotoelectric conversion section.

-   (3)

The solid-state imaging device according to (1) or (2), wherein

the first gate is disposed on a same plane as the accumulationelectrode.

-   (4)

The solid-state imaging device according to (1) or (2), wherein

the first gate is disposed on a side opposite to the floating diffusionregion sandwiching the accumulation electrode.

-   (5)

The solid-state imaging device according to (1) or (2), wherein

the first gate is disposed on a side opposite to the first semiconductorlayer sandwiching the accumulation electrode.

-   (6)

The solid-state imaging device according to (4) or (5), wherein

a part of the first gate overlaps the accumulation electrode in adirection vertical to a main plane of the first semiconductor layer.

-   (7)

The solid-state imaging device according to any one of (1) to (6),wherein

each of the pixels further includes a shield layer disposed at aboundary with an adjacent pixel and forming a potential barrier thatsuppresses outflow of a charge from each pixel to an adjacent pixel.

-   (8)

The solid-state imaging device according to (7), wherein

the shield layer is a fixed charge film having a same polarity as apolarity of a charge generated by photoelectric conversion by thephotoelectric conversion section.

-   (9)

The solid-state imaging device according to (7) or (8), wherein

the shield layer is disposed on a same plane as the accumulationelectrode.

-   (10)

The solid-state imaging device according to (7) or (8), wherein

the shield layer is disposed on a side opposite to the floatingdiffusion region sandwiching the accumulation electrode.

-   (11)

The solid-state imaging device according to (7) or (8), wherein

the shield layer is disposed on a side opposite to the firstsemiconductor layer sandwiching the accumulation electrode.

-   (12)

The solid-state imaging device according to (10) or (11), wherein

a part of the shield layer overlaps the accumulation electrode in adirection vertical to a main plane of the first semiconductor layer.

-   (13)

The solid-state imaging device according to any one of (1) to (12),wherein

each of the pixels further includes

a second gate disposed close to the wiring at a position closer to thefloating diffusion region than the first gate, and

a memory electrode disposed close to the wiring at a position betweenthe first gate and the second gate.

-   (14)

The solid-state imaging device according to (13), wherein

each of the pixels further includes a second semiconductor layerpositioned between the first semiconductor layer and the floatingdiffusion region,

the wiring includes

a first wiring extending from the first semiconductor layer andconnected to the second semiconductor layer, and

a second wiring extending from the second semiconductor layer andconnected to the floating diffusion region,

the first gate is disposed close to the first wiring,

the memory electrode is disposed close to the second semiconductorlayer, and

the second gate is disposed close to the second wiring.

-   (15)

The solid-state imaging device according to any one of (1) to (14),wherein

a cross section of the wiring is circular or polygonal.

-   (16)

The solid-state imaging device according to any one of (1) to (15),wherein

the wiring has a tapered shape having diameter decreasing from the firstsemiconductor layer to the floating diffusion region.

-   (17)

The solid-state imaging device according to any one of (1) to (16),wherein

adjacent pixels among the plurality of pixels are connected to a commonfloating diffusion region.

-   (18)

The solid-state imaging device according to any one of (1) to (17),wherein

the photoelectric conversion section is an organic film.

-   (19)

The solid-state imaging device according to any one of (1) to (18),wherein

the first semiconductor layer includes

a first layer in contact with the photoelectric conversion section, and

a second layer positioned on a side opposite to the photoelectricconversion section sandwiching the first layer.

-   (20)

An electronic apparatus including:

the solid-state imaging device according to any one of (1) to (19);

a lens that forms an image of incident light on the solid-state imagingdevice; and

a processing circuit that executes predetermined processing on a signaloutput from the solid-state imaging device.

REFERENCE SIGNS LIST

1 ELECTRONIC APPARATUS

10, 10-1 to 10-N, 10A, 10 a, 10 b RGB PIXEL

11, 15 TRANSFER GATE

12, 22 RESET TRANSISTOR

13, 23 AMPLIFICATION TRANSISTOR

14, 24 SELECTION TRANSISTOR

16 MEMORY ELECTRODE

20 IR PIXEL

21 TRANSFER TRANSISTOR

25 DISCHARGE TRANSISTOR

31, 31 r, 31 g, 31 b COLOR FILTER

32 SEALING FILM

33 TRANSPARENT ELECTRODE

34 PHOTOELECTRIC CONVERSION FILM

35 SEMICONDUCTOR LAYER

35A FIRST SEMICONDUCTOR LAYER

35B SECOND SEMICONDUCTOR LAYER

35 a FIRST LAYER

35 b SECOND LAYER

36 READOUT ELECTRODE

37 ACCUMULATION ELECTRODE

41 IR FILTER

42 p-WELL REGION

43 p-TYPE SEMICONDUCTOR REGION

44 n-TYPE SEMICONDUCTOR REGION

45 LONGITUDINAL TRANSISTOR

51 ON-CHIP LENS

52 PLANARIZATION FILM

53 INSULATING LAYER

54 PIXEL ISOLATION SECTION

55 FIXED CHARGE FILM

56 INTERLAYER INSULATING FILM

57, 57B SHIELD ELECTRODE

58, 59 CHARGE

60 SEMICONDUCTOR WIRING

61 to 66, 72, 73 WIRING

67 SHIELD CHARGE FILM

81, 83, 84 FIXED CHARGE FILM

81 a OPENING

82 INSULATING FILM

91 GATE ELECTRODE

100 IMAGE SENSOR

101 PIXEL ARRAY SECTION

102 VERTICAL DRIVE CIRCUIT

103 SIGNAL PROCESSING CIRCUIT

103 a AD CONVERSION CIRCUIT

104 HORIZONTAL DRIVE CIRCUIT

105 SYSTEM CONTROL CIRCUIT

108 DATA PROCESSING UNIT

109 DATA STORAGE SECTION

110, 110A UNIT PIXEL

121 LIGHT RECEIVING CHIP

122 CIRCUIT CHIP

901 SUBJECT

1010 LASER LIGHT SOURCE

1011 LIGHT SOURCE DRIVING UNIT

1012 VCSEL

1021 SENSOR CONTROL UNIT

1022 LIGHT RECEIVING SECTION

1030 IRRADIATION LENS

1040 IMAGING LENS

1050 SYSTEM CONTROL SECTION

1100 APPLICATION PROCESSOR

LD PIXEL DRIVE LINE

MEM MEMORY

PD1, PD2 PHOTOELECTRIC CONVERSION SECTION

VSL, VSL1, VSL2 VERTICAL SIGNAL LINE

1. A solid-state imaging device including: a plurality of pixelsarranged in a matrix, wherein each of the pixels includes a firstsemiconductor layer, a photoelectric conversion section disposed on thefirst semiconductor layer on a side of a first surface, an accumulationelectrode disposed on the first semiconductor layer close to a side of asecond surface on a side opposite to the first surface, a wiringextending from the second surface of the first semiconductor layer, afloating diffusion region connected to the first semiconductor layer viathe wiring, and a first gate that forms a potential barrier in a chargeflow path from the first semiconductor layer to the floating diffusionregion via the wiring.
 2. The solid-state imaging device according toclaim 1, wherein the first gate is a fixed charge film having a samepolarity as a polarity of a charge generated by photoelectric conversionby the photoelectric conversion section.
 3. The solid-state imagingdevice according to claim 1, wherein the first gate is disposed on asame plane as the accumulation electrode.
 4. The solid-state imagingdevice according to claim 1, wherein the first gate is disposed on aside opposite to the floating diffusion region sandwiching theaccumulation electrode.
 5. The solid-state imaging device according toclaim 1, wherein the first gate is disposed on a side opposite to thefirst semiconductor layer sandwiching the accumulation electrode.
 6. Thesolid-state imaging device according to claim 4, wherein a part of thefirst gate overlaps the accumulation electrode in a direction verticalto a main plane of the first semiconductor layer.
 7. The solid-stateimaging device according to claim 1, wherein each of the pixels furtherincludes a shield layer disposed at a boundary with an adjacent pixeland forming a potential barrier that suppresses outflow of a charge fromeach pixel to an adjacent pixel.
 8. The solid-state imaging deviceaccording to claim 7, wherein the shield layer is a fixed charge filmhaving a same polarity as a polarity of a charge generated byphotoelectric conversion by the photoelectric conversion section.
 9. Thesolid-state imaging device according to claim 7, wherein the shieldlayer is disposed on a same plane as the accumulation electrode.
 10. Thesolid-state imaging device according to claim 7, wherein the shieldlayer is disposed on a side opposite to the floating diffusion regionsandwiching the accumulation electrode.
 11. The solid-state imagingdevice according to claim 7, wherein the shield layer is disposed on aside opposite to the first semiconductor layer sandwiching theaccumulation electrode.
 12. The solid-state imaging device according toclaim 10, wherein a part of the shield layer overlaps the accumulationelectrode in a direction vertical to a main plane of the firstsemiconductor layer.
 13. The solid-state imaging device according toclaim 1, wherein each of the pixels further includes a second gatedisposed close to the wiring at a position closer to the floatingdiffusion region than the first gate, and a memory electrode disposedclose to the wiring at a position between the first gate and the secondgate.
 14. The solid-state imaging device according to claim 13, whereineach of the pixels further includes a second semiconductor layerpositioned between the first semiconductor layer and the floatingdiffusion region, the wiring includes a first wiring extending from thefirst semiconductor layer and connected to the second semiconductorlayer, and a second wiring extending from the second semiconductor layerand connected to the floating diffusion region, the first gate isdisposed close to the first wiring, the memory electrode is disposedclose to the second semiconductor layer, and the second gate is disposedclose to the second wiring.
 15. The solid-state imaging device accordingto claim 1, wherein a cross section of the wiring is circular orpolygonal.
 16. The solid-state imaging device according to claim 1,wherein the wiring has a tapered shape having diameter decreasing fromthe first semiconductor layer to the floating diffusion region.
 17. Thesolid-state imaging device according to claim 1, wherein adjacent pixelsamong the plurality of pixels are connected to a common floatingdiffusion region.
 18. The solid-state imaging device according to claim1, wherein the photoelectric conversion section is an organic film. 19.The solid-state imaging device according to claim 1, wherein the firstsemiconductor layer includes a first layer in contact with thephotoelectric conversion section, and a second layer positioned on aside opposite to the photoelectric conversion section sandwiching thefirst layer.
 20. An electronic apparatus including: the solid-stateimaging device according to claim 1; a lens that forms an image ofincident light on the solid-state imaging device; and a processingcircuit that executes predetermined processing on a signal output fromthe solid-state imaging device.